REPRO:

1. run uia2atk/test/samples/toolstripdropdown_toolstripbutton.py 
2. run accerciser
2. in accerciser, expand 'ipy' in the tree view on the left, expand 'frame'

RESULTS: 

application crashed

Exception in Gtk# callback delegate
  Note: Applications can use GLib.ExceptionManager.UnhandledException to handle the exception.
System.ArgumentException: The provider for CheckBox should implement the Toggle pattern
  at UiaAtkBridge.CheckBoxButton..ctor (IRawElementProviderSimple provider) [0x00000] 
  at UiaAtkBridge.ToggleButton..ctor (IRawElementProviderSimple provider) [0x00000] 
  at UiaAtkBridge.AutomationBridge.HandleNewButtonControlType (IRawElementProviderSimple provider, UiaAtkBridge.ParentAdapter parentObject) [0x00000] 
  at UiaAtkBridge.AutomationBridge.HandleElementAddition (IRawElementProviderSimple simpleProvider) [0x00000] 
  at UiaAtkBridge.AutomationBridge.RaiseStructureChangedEvent (System.Object provider, System.Windows.Automation.StructureChangedEventArgs e) [0x00000] 
  at System.Windows.Automation.Provider.AutomationInteropProvider.RaiseStructureChangedEvent (IRawElementProviderSimple provider, System.Windows.Automation.StructureChangedEventArgs e) [0x00000] 
  at UiaAtkBridge.AutomationBridge.AddChildrenToParent (IRawElementProviderSimple provider) [0x00000] 
  at UiaAtkBridge.ParentAdapter.RequestChildren () [0x00000] 
  at UiaAtkBridge.ParentAdapter.OnGetNChildren () [0x00000] 
  at Atk.Object.NChildren_cb (IntPtr raw) [0x00000] 
   at GLib.ExceptionManager.RaiseUnhandledException(System.Exception e, Boolean is_terminal)
   at Atk.Object.NChildren_cb(IntPtr raw)
   at GLib.MainLoop.g_main_loop_run(IntPtr )
   at GLib.MainLoop.Run()
   at UiaAtkBridge.Monitor.GLibMainLoopThread()