Docking manager gives error when i close docked control

Hi,
When i close a docked control on my docking manager and try disposing my control in the dock visibility changing event thrown by the docking manager, i get the fllowing error after all the disposing has been taken care of in my code. aditionally i make sure i set dockingmanager.setenabledocking for the control to false.
the error is this :
(System.NullReferenceException) - Object reference not set to an instance of an object.

the stack trace is this:
Syncfusion.Windows.Forms.Tools.DockHostController.CloseController()
at Syncfusion.Windows.Forms.Tools.DockHostController.HandleMouseUpImp(MouseButtons button, Point pt)
at Syncfusion.Windows.Forms.Tools.DockHost.OnMouseUp(MouseEventArgs 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.ScrollableControl.WndProc(Message& m)
at System.Windows.Forms.ContainerControl.WndProc(Message& m)
at Syncfusion.Windows.Forms.Tools.DockHost.WndProc(Message& msg)
at System.Windows.Forms.ControlNativeWindow.OnMessage(Message& m)
at System.Windows.Forms.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.ComponentManager.System.Windows.Forms.UnsafeNativeMethods+IMsoComponentManager.FPushMessageLoop(Int32 dwComponentID, Int32 reason, Int32 pvLoopData)
at System.Windows.Forms.ThreadContext.RunMessageLoopInner(Int32 reason, ApplicationContext context)
at System.Windows.Forms.ThreadContext.RunMessageLoop(Int32 reason, ApplicationContext context)
at System.Windows.Forms.Application.Run()


could u please throw some light on why u think this could be happening. is there a standard way of disabling a control on dockingManager.

My syncfusion version is 4.1.0.50

how rude.....
yes i realize there are similar queries in the forum, but they werent getting the same error as me.
I expected some kind of reply.

Hi Anisha,

Sorry for the delay in getting back to you.

It will be very helpful if you povide us a sample of illustrating the issue that would help us to find the solution soon.

Thank you for using Syncfusion products.

Regards,
Jaya