Yes, this is known issue in our RadForm. The issue is observed in a maximized RadForm on a Windows 7 OS with a disable Aero or in a maximized RadForm on a remote machine. We already have it logged in our Feedback Portal. You can track its progress, subscribe for status changes and add your vote/comment to it on the following link - feedback Item. The issue has already been addressed and the fix will be introduced in the next official release, which is scheduled for September.
If you can not wait until then, feel free to use the suggested workaround from the issue page.
I hope this will help you. Let me know if you have any other questions.
Regards,
Ralitsa
Telerik by Progress
Check out the Windows Forms project converter, which aids the conversion process from standard Windows Forms applications written in C# or VB to Telerik UI for WinForms.For more information check out this blog post and share your thoughts.