dialogs must be user-initiated - RadUpload control of telerik for silverlight 4

I am upgrading my application from silverlight 3 to silverlight 4 and using latest telerik binaries which is for silver开发者_如何学编程light 4, I have one issue in RadUpload.

When RadUpload.ShowFileDialog(); method called it will through the error as follows

System.Security.SecurityException: Dialogs must be user-initiated.

Can anyone help me out in this issue?

Thanks in Advances Bhushan Deshmukh

I've given up on Telerik controls, but the one thing that they are great at is responding to the forums on their site. I'm sure if you moved this to the Telerik site you'll receive an answer within one or two days, if one is not posted already.

http://www.telerik.com/community/forums/silverlight/upload/dialogs-must-be-user-initiated.aspx