diff --git a/lib/cosmos/gui/choosers/telemetry_chooser.rb b/lib/cosmos/gui/choosers/telemetry_chooser.rb
index 7289e09d6..d1f372c16 100644
--- a/lib/cosmos/gui/choosers/telemetry_chooser.rb
+++ b/lib/cosmos/gui/choosers/telemetry_chooser.rb
@@ -134,7 +134,6 @@ def initialize(
       @item_changed_callback = nil
       @select_button_callback = nil
       @support_latest = support_latest
-      update()
     end
 
     # Update items
diff --git a/lib/cosmos/gui/dialogs/progress_dialog.rb b/lib/cosmos/gui/dialogs/progress_dialog.rb
index 2b7212725..c931f9f6b 100644
--- a/lib/cosmos/gui/dialogs/progress_dialog.rb
+++ b/lib/cosmos/gui/dialogs/progress_dialog.rb
@@ -125,6 +125,8 @@ def initialize(parent, title, width = 500, height = 300, show_overall = true, sh
 
       @thread = nil
       @cancel_callback = nil
+      @overall_progress = 0
+      @step_progress = 0
     end
 
     def self.canceled?
@@ -199,17 +201,21 @@ def complete
     end
 
     def set_step_progress (value)
-      unless @complete
+      progress_int = (value * 100).to_i
+      if !@complete and @step_progress != progress_int
+        @step_progress = progress_int
         Qt.execute_in_main_thread(false) do
-          @step_bar.setValue(value * 100.0) if @step_bar
+          @step_bar.setValue(progress_int) if @step_bar
         end
       end
     end
 
     def set_overall_progress (value)
-      unless @complete
+      progress_int = (value * 100).to_i
+      if !@complete and @overall_progress != progress_int
+        @overall_progress = progress_int
         Qt.execute_in_main_thread(false) do
-          @overall_bar.setValue(value * 100.0) if @overall_bar
+          @overall_bar.setValue(progress_int) if @overall_bar
         end
       end
     end
diff --git a/lib/cosmos/gui/dialogs/splash.rb b/lib/cosmos/gui/dialogs/splash.rb
index 7b2d5c6d7..92cf5b740 100644
--- a/lib/cosmos/gui/dialogs/splash.rb
+++ b/lib/cosmos/gui/dialogs/splash.rb
@@ -37,19 +37,27 @@ def initialize(parent)
         layout.addWidget(@message_box)
         @progress_bar = Qt::ProgressBar.new
         layout.addWidget(@progress_bar)
-
         setLayout(layout)
+
+        @progress = 0
+        @complete = false
       end
 
       def message=(message)
-        Qt.execute_in_main_thread(true) do
-          @message_box.setText(message)
+        unless @complete
+          Qt.execute_in_main_thread(false) do
+            @message_box.setText(message)
+          end
         end
       end
 
       def progress=(progress)
-        Qt.execute_in_main_thread(true) do
-          @progress_bar.setValue(progress * 100)
+        progress_int = (progress * 100).to_i
+        if !@complete and @progress != progress_int
+          @progress = progress_int
+          Qt.execute_in_main_thread(false) do
+            @progress_bar.setValue(progress_int)
+          end
         end
       end
 
@@ -82,7 +90,6 @@ def self.execute(parent, wait_for_complete = false, &block)
       #   Qt.execute_in_main_thread(true) do
       #     < Update the GUI >
       #   end
-      complete = false
       Thread.new do
         error = nil
         begin
@@ -91,6 +98,8 @@ def self.execute(parent, wait_for_complete = false, &block)
           error = e
         end
 
+        @complete = true
+
         # If the block threw an error show it before allowing the application to crash
         if error
           Qt.execute_in_main_thread(true) do
@@ -101,12 +110,25 @@ def self.execute(parent, wait_for_complete = false, &block)
         Qt.execute_in_main_thread(true) do
           # Once the block has completed we hide and dispose the dialog to allow the main application to take over
           dialog.hide
-          dialog.dispose unless wait_for_complete
+
+          unless wait_for_complete
+            # Need to make sure all Qt.execute_in_main_thread() have completed before disposing or
+            # we will segfault
+            Qt::RubyThreadFix.queue.pop.call until Qt::RubyThreadFix.queue.empty?
+
+            dialog.dispose
+          end
         end
-        complete = true
       end
-      dialog.exec if wait_for_complete
-      dialog.dispose if wait_for_complete
+      if wait_for_complete
+        dialog.exec
+
+        # Need to make sure all Qt.execute_in_main_thread() have completed before disposing or
+        # we will segfault
+        Qt::RubyThreadFix.queue.pop.call until Qt::RubyThreadFix.queue.empty?
+
+        dialog.dispose
+      end
     end
   end
 
diff --git a/lib/cosmos/packets/limits.rb b/lib/cosmos/packets/limits.rb
index d53c80dcd..849078f38 100644
--- a/lib/cosmos/packets/limits.rb
+++ b/lib/cosmos/packets/limits.rb
@@ -201,7 +201,8 @@ def get(target_name, packet_name, item_name, limits_set = nil)
     # @return [Array<limits_set, persistence, enabled, red_low, yellow_low, red_high, yellow_high, green_low (optional), green_high (optional)] Limits information
     def set(target_name, packet_name, item_name, red_low, yellow_low, yellow_high, red_high, green_low = nil, green_high = nil, limits_set = :CUSTOM, persistence = nil, enabled = true)
       packet = get_packet(target_name, packet_name)
-      limits = packet.get_item(item_name).limits
+      item = packet.get_item(item_name)
+      limits = item.limits
       if limits_set
         limits_set = limits_set.to_s.upcase.intern
       else
@@ -231,7 +232,7 @@ def set(target_name, packet_name, item_name, red_low, yellow_low, yellow_high, r
       end
       limits.enabled = enabled
       limits.persistence_setting = Integer(persistence) if persistence
-      packet.update_limits_items_cache
+      packet.update_limits_items_cache(item)
       @config.limits_sets << limits_set
       @config.limits_sets.uniq!
       return [limits_set, limits.persistence_setting, limits.enabled, limits_for_set[0], limits_for_set[1], limits_for_set[2], limits_for_set[3], limits_for_set[4], limits_for_set[5]]
diff --git a/lib/cosmos/packets/packet.rb b/lib/cosmos/packets/packet.rb
index c7935f177..854919e1d 100644
--- a/lib/cosmos/packets/packet.rb
+++ b/lib/cosmos/packets/packet.rb
@@ -279,7 +279,7 @@ def define_item(name, bit_offset, bit_size, data_type, array_size = nil, endiann
     def define(item)
       item = super(item)
       update_id_items(item)
-      update_limits_items_cache()
+      update_limits_items_cache(item)
       item
     end
 
@@ -532,16 +532,19 @@ def disable_limits(name)
       end
     end
 
-    # Force the packet to update its knowledge of items with limits. This is an
-    # optimization so we don't have to iterate through all the items when
+    # Add an item to the limits items cache if necessary.
+    # You MUST call this after adding limits to an item
+    #This is an optimization so we don't have to iterate through all the items when
     # checking for limits.
-    def update_limits_items_cache
-      # Collect only the items who have limits values or states and then
-      # compact the array to remove all the nil values
-      @limits_items = @sorted_items.collect do |item|
-        item if item.limits.values || item.state_colors
+    def update_limits_items_cache(item)
+      if item.limits.values || item.state_colors
+        @limits_items ||= []
+        @limits_items_hash ||= {}
+        unless @limits_items_hash[item]
+          @limits_items << item
+          @limits_items_hash[item] = true
+        end
       end
-      @limits_items.compact!
     end
 
     # Return an array of arrays indicating all items in the packet that are out of limits
diff --git a/lib/cosmos/packets/parsers/limits_parser.rb b/lib/cosmos/packets/parsers/limits_parser.rb
index 80a7b9c2f..9f0baeea4 100644
--- a/lib/cosmos/packets/parsers/limits_parser.rb
+++ b/lib/cosmos/packets/parsers/limits_parser.rb
@@ -47,7 +47,7 @@ def create_limits(packet, item, warnings)
       item.limits.persistence_setting = get_persistence()
       item.limits.persistence_count = 0
 
-      packet.update_limits_items_cache
+      packet.update_limits_items_cache(item)
       limits_set
     end
 
diff --git a/lib/cosmos/packets/parsers/state_parser.rb b/lib/cosmos/packets/parsers/state_parser.rb
index 0638ad5d2..4f0a0ec76 100644
--- a/lib/cosmos/packets/parsers/state_parser.rb
+++ b/lib/cosmos/packets/parsers/state_parser.rb
@@ -85,7 +85,7 @@ def parse_additional_parameters(packet, cmd_or_tlm, item)
         get_hazardous(item)
       else
         get_state_colors(item)
-        packet.update_limits_items_cache
+        packet.update_limits_items_cache(item)
       end
     end
 
diff --git a/lib/cosmos/tools/tlm_extractor/tlm_extractor.rb b/lib/cosmos/tools/tlm_extractor/tlm_extractor.rb
index f0c46d62e..83ce24371 100644
--- a/lib/cosmos/tools/tlm_extractor/tlm_extractor.rb
+++ b/lib/cosmos/tools/tlm_extractor/tlm_extractor.rb
@@ -92,6 +92,7 @@ def initialize(options)
         @tlm_extractor_config = TlmExtractorConfig.new(options.config_file)
         @tlm_extractor_processor = TlmExtractorProcessor.new
         Qt.execute_in_main_thread(true) do
+          @telemetry_chooser.update
           sync_config_to_gui()
         end
 
diff --git a/lib/cosmos/tools/tlm_grapher/data_object_adders/xy_data_object_adder.rb b/lib/cosmos/tools/tlm_grapher/data_object_adders/xy_data_object_adder.rb
index 78aa1dd54..77cd815ae 100644
--- a/lib/cosmos/tools/tlm_grapher/data_object_adders/xy_data_object_adder.rb
+++ b/lib/cosmos/tools/tlm_grapher/data_object_adders/xy_data_object_adder.rb
@@ -38,6 +38,7 @@ def initialize(parent, orientation = Qt::Horizontal)
 
       # Chooser for packet and y item
       @telemetry_chooser = TelemetryChooser.new(self, orientation, true, false, true, true)
+      @telemetry_chooser.update
       @overall_frame.addWidget(@telemetry_chooser)
       @telemetry_chooser.target_changed_callback = method(:packet_changed_callback)
       @telemetry_chooser.packet_changed_callback = method(:packet_changed_callback)
diff --git a/lib/cosmos/tools/tlm_grapher/data_object_editors/housekeeping_data_object_editor.rb b/lib/cosmos/tools/tlm_grapher/data_object_editors/housekeeping_data_object_editor.rb
index 7b1fca435..c11157239 100644
--- a/lib/cosmos/tools/tlm_grapher/data_object_editors/housekeeping_data_object_editor.rb
+++ b/lib/cosmos/tools/tlm_grapher/data_object_editors/housekeeping_data_object_editor.rb
@@ -43,6 +43,7 @@ def set_data_object(data_object)
 
       # Telemetry Chooser for housekeeping item
       @telemetry_chooser = TelemetryChooser.new(self, Qt::Vertical, true, false, true)
+      @telemetry_chooser.update
       @telemetry_chooser.set_item(data_object.target_name, data_object.packet_name, data_object.item_name)
       @telemetry_chooser.target_changed_callback = method(:target_packet_changed_callback)
       @telemetry_chooser.packet_changed_callback = method(:target_packet_changed_callback)
diff --git a/lib/cosmos/tools/tlm_grapher/data_object_editors/xy_data_object_editor.rb b/lib/cosmos/tools/tlm_grapher/data_object_editors/xy_data_object_editor.rb
index c87e54e8e..d6b7fa031 100644
--- a/lib/cosmos/tools/tlm_grapher/data_object_editors/xy_data_object_editor.rb
+++ b/lib/cosmos/tools/tlm_grapher/data_object_editors/xy_data_object_editor.rb
@@ -50,6 +50,7 @@ def set_data_object(data_object)
 
       # Telemetry Chooser for x item
       @telemetry_chooser = TelemetryChooser.new(self, Qt::Vertical, true, false)
+      @telemetry_chooser.update
       @telemetry_chooser.set_item(data_object.target_name, data_object.packet_name, data_object.y_item_name)
       @telemetry_chooser.target_changed_callback = method(:target_packet_changed_callback)
       @telemetry_chooser.packet_changed_callback = method(:target_packet_changed_callback)
diff --git a/spec/packets/packet_spec.rb b/spec/packets/packet_spec.rb
index 744c42975..438df9379 100644
--- a/spec/packets/packet_spec.rb
+++ b/spec/packets/packet_spec.rb
@@ -572,6 +572,7 @@ module Cosmos
         i = p.get_item("TEST1")
         i.states = {"TRUE"=>1,"FALSE"=>0}
         i.state_colors = {"TRUE"=>:GREEN,"FALSE"=>:RED}
+        p.update_limits_items_cache(i)
         p.write("TEST1",0)
         p.enable_limits("TEST1")
         p.append_item("test2", 16, :UINT)
@@ -579,7 +580,7 @@ module Cosmos
         i.limits.values = {:DEFAULT=>[1,2,4,5]}
         p.write("TEST2",3)
         p.enable_limits("TEST2")
-        p.update_limits_items_cache
+        p.update_limits_items_cache(i)
         p.check_limits
 
         vals = p.read_all_with_limits_states
@@ -813,14 +814,17 @@ module Cosmos
       it "calls the limits_change_callback for all non STALE items" do
         p = Packet.new("tgt","pkt")
         p.append_item("test1", 8, :UINT)
-        p.get_item("TEST1").limits.values = {:DEFAULT=>[1,2,4,5]}
+        i = p.get_item("TEST1")
+        i.limits.values = {:DEFAULT=>[1,2,4,5]}
+        p.update_limits_items_cache(i)
         p.append_item("test2", 16, :UINT)
-        p.get_item("TEST2").limits.values = {:DEFAULT=>[1,2,4,5]}
+        i = p.get_item("TEST2")
+        i.limits.values = {:DEFAULT=>[1,2,4,5]}
+        p.update_limits_items_cache(i)
         p.write("TEST1",3)
         p.write("TEST2",3)
         p.enable_limits("TEST1")
         p.enable_limits("TEST2")
-        p.update_limits_items_cache
 
         callback = double("callback", :call => true)
         p.limits_change_callback = callback
@@ -845,11 +849,11 @@ module Cosmos
 
         test1 = p.get_item("TEST1")
         test1.limits.values = {:DEFAULT=>[1,2,4,5]}
-        p.update_limits_items_cache
+        p.update_limits_items_cache(test1)
         expect(p.limits_items).to eql [test1]
         test2 = p.get_item("TEST2")
         test2.limits.values = {:DEFAULT=>[1,2,4,5]}
-        p.update_limits_items_cache
+        p.update_limits_items_cache(test2)
         expect(p.limits_items).to eql [test1, test2]
       end
     end
@@ -858,14 +862,17 @@ module Cosmos
       it "returns an array indicating all items out of limits" do
         p = Packet.new("tgt","pkt")
         p.append_item("test1", 8, :UINT)
-        p.get_item("TEST1").limits.values = {:DEFAULT=>[1,2,4,5]}
+        i = p.get_item("TEST1")
+        i.limits.values = {:DEFAULT=>[1,2,4,5]}
+        p.update_limits_items_cache(i)
         p.enable_limits("TEST1")
         p.write("TEST1",3)
         p.append_item("test2", 16, :UINT)
-        p.get_item("TEST2").limits.values = {:DEFAULT=>[1,2,4,5]}
+        i = p.get_item("TEST2")
+        i.limits.values = {:DEFAULT=>[1,2,4,5]}
+        p.update_limits_items_cache(i)
         p.write("TEST2",3)
         p.enable_limits("TEST2")
-        p.update_limits_items_cache
         p.check_limits
         expect(p.out_of_limits).to eql []
 
@@ -882,12 +889,15 @@ module Cosmos
       it "sets all limits states to the given state" do
         p = Packet.new("tgt","pkt")
         p.append_item("test1", 8, :UINT)
-        p.get_item("TEST1").limits.values = {:DEFAULT=>[1,2,4,5]}
+        i = p.get_item("TEST1")
+        i.limits.values = {:DEFAULT=>[1,2,4,5]}
+        p.update_limits_items_cache(i)
         p.enable_limits("TEST1")
         p.append_item("test2", 16, :UINT)
-        p.get_item("TEST2").limits.values = {:DEFAULT=>[1,2,4,5]}
+        i = p.get_item("TEST2")
+        i.limits.values = {:DEFAULT=>[1,2,4,5]}
+        p.update_limits_items_cache(i)
         p.enable_limits("TEST2")
-        p.update_limits_items_cache
         expect(p.out_of_limits).to eql []
 
         PacketItemLimits::OUT_OF_LIMITS_STATES.each do |state|
@@ -927,6 +937,7 @@ module Cosmos
           expect(test1.limits.enabled).to be_falsey
           test1.states = {"TRUE"=>1,"FALSE"=>0}
           test1.state_colors = {"TRUE"=>:GREEN,"FALSE"=>:RED}
+          @p.update_limits_items_cache(test1)
           @p.write("TEST1", 0)
           @p.enable_limits("TEST1")
           test2 = @p.get_item("TEST2")
@@ -935,7 +946,7 @@ module Cosmos
           test2.state_colors = {"TRUE"=>:RED,"FALSE"=>:GREEN}
           @p.write("TEST2", 0)
           @p.enable_limits("TEST2")
-          @p.update_limits_items_cache
+          @p.update_limits_items_cache(test2)
 
           # Mock the callback so we can see if it is called properly
           callback = double("callback", :call => true)
@@ -963,18 +974,20 @@ module Cosmos
           @test1 = @p.get_item("TEST1")
           expect(@test1.limits.enabled).to be_falsey
           @test1.limits.values = {:DEFAULT=>[1,2,4,5]} # red yellow
+          @p.update_limits_items_cache(@test1)
           @p.enable_limits("TEST1")
 
           @test2 = @p.get_item("TEST2")
           expect(@test2.limits.enabled).to be_falsey
           @test2.limits.values = {:DEFAULT=>[1,2,6,7,3,5]} # red yellow and blue
+          @p.update_limits_items_cache(@test2)
           @p.enable_limits("TEST2")
 
           @test3 = @p.get_item("TEST3")
           expect(@test3.limits.enabled).to be_falsey
           @test3.limits.values = {:DEFAULT=>[1,1.5,2.5,3]} # red yellow
+          @p.update_limits_items_cache(@test3)
           @p.enable_limits("TEST3")
-          @p.update_limits_items_cache
 
           # Mock the callback so we can see if it is called properly
           @callback = double("callback", :call => true)
@@ -1224,12 +1237,15 @@ module Cosmos
       it "sets all limits states to stale" do
         p = Packet.new("tgt","pkt")
         p.append_item("test1", 8, :UINT)
-        p.get_item("TEST1").limits.values = {:DEFAULT=>[1,2,4,5]}
+        i = p.get_item("TEST1")
+        i.limits.values = {:DEFAULT=>[1,2,4,5]}
+        p.update_limits_items_cache(i)
         p.enable_limits("TEST1")
         p.append_item("test2", 16, :UINT)
-        p.get_item("TEST2").limits.values = {:DEFAULT=>[1,2,4,5]}
+        i = p.get_item("TEST2")
+        i.limits.values = {:DEFAULT=>[1,2,4,5]}
+        p.update_limits_items_cache(i)
         p.enable_limits("TEST2")
-        p.update_limits_items_cache
         expect(p.out_of_limits).to eql []
 
         expect(p.stale).to be_truthy