Thank you for writing.
Despite my efforts, I was not able to reproduce this issue. It might have something specific in your project which causes this. Therefore, I would ask you to send some more detailed steps of reproducing and you might as well post the code you are using. This will let me investigate the issue and provide you with an adequate answer.
I am looking forward to hearing from you.
the Telerik team
Q2’11 SP1 of RadControls for WinForms is available for download (see what's new); also available is the Q3'11 Roadmap for Telerik Windows Forms controls.