I found a problem when use RadHtmlPlaceHolder with RadExpander. I create a small application to show this. Please see the codes.

If I expand the button and then quickly switch between tabs for several times. The application will more and more slow. Finally it will crash with message "Message:Error HRESULT E_FAIL has been returned from a call to a COM component".

If I use Textblock instead of RadHtmlPlaceHolder, application will run correctly.
Any suggestions?