I am going to copy the answer from the other thread, so the community can benefit from it:
I logged the issue in our issue tracking system. I updated also your Telerik points accordingly. The fix will be available with our next official release - Q2 2011.
the Telerik team
Q1’11 SP1 of RadControls for WinForms is available for download
; also available is the Q2'11 Roadmap
for Telerik Windows Forms controls.