Using an UltraExplorerBar (7.3) in Outlook mode, when you double click an item it occasionaly throws the following error.  I'm not evening trying to handle the double click event.

System.NullReferenceException was unhandled
  Message="Object reference not set to an instance of an object."
  Source="Infragistics2.Win.UltraWinExplorerBar.v7.3"
  StackTrace:
       at Infragistics.Win.UltraWinExplorerBar.UltraExplorerBar.ItemFromPoint(Point point)
       at Infragistics.Win.UltraWinExplorerBar.UltraExplorerBar.OnDoubleClick(EventArgs e)
       at System.Windows.Forms.Control.WmMouseUp(Message& m, MouseButtons button, Int32 clicks)
       at System.Windows.Forms.Control.WndProc(Message& m)
       at System.Windows.Forms.Control.ControlNativeWindow.OnMessage(Message& m)
       at System.Windows.Forms.Control.ControlNativeWindow.WndProc(Message& m)
       at System.Windows.Forms.NativeWindow.DebuggableCallback(IntPtr hWnd, Int32 msg, IntPtr wparam, IntPtr lparam)
       at System.Windows.Forms.UnsafeNativeMethods.DispatchMessageW(MSG& msg)
       at System.Windows.Forms.Application.ComponentManager.System.Windows.Forms.UnsafeNativeMethods.IMsoComponentManager.FPushMessageLoop(Int32 dwComponentID, Int32 reason, Int32 pvLoopData)
       at System.Windows.Forms.Application.ThreadContext.RunMessageLoopInner(Int32 reason, ApplicationContext context)
       at System.Windows.Forms.Application.ThreadContext.RunMessageLoop(Int32 reason, ApplicationContext context)
       at System.Windows.Forms.Application.Run(ApplicationContext context)
       at Microsoft.VisualBasic.ApplicationServices.WindowsFormsApplicationBase.OnRun()
       at Microsoft.VisualBasic.ApplicationServices.WindowsFormsApplicationBase.DoApplicationModel()
       at Microsoft.VisualBasic.ApplicationServices.WindowsFormsApplicationBase.Run(String[ commandLine)
       at InFocus.My.MyApplication.Main(String[ Args) in 17d14f5c-a337-4978-8281-53493378c1071.vb:line 81
       at System.AppDomain._nExecuteAssembly(Assembly assembly, String[ args)
       at System.AppDomain.nExecuteAssembly(Assembly assembly, String[ args)
       at System.Runtime.Hosting.ManifestRunner.Run(Boolean checkAptModel)
       at System.Runtime.Hosting.ManifestRunner.ExecuteAsAssembly()
       at System.Runtime.Hosting.ApplicationActivator.CreateInstance(ActivationContext activationContext, String[ activationCustomData)
       at System.Runtime.Hosting.ApplicationActivator.CreateInstance(ActivationContext activationContext)
       at Microsoft.VisualStudio.HostingProcess.HostProc.RunUsersAssemblyDebugInZone()
       at System.Threading.ThreadHelper.ThreadStart_Context(Object state)
       at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state)
       at System.Threading.ThreadHelper.ThreadStart()