Hi Rok,
Thank you for contacting us.
There seems to be a performance issue with drawing the
RadPanel's child controls. I was able to achieve the described behavior when I added over 100 buttons. With only 8 buttons on the panel everything looked fine. The following workaround did the trick for me. Please refer to the code snippet below (I suppose that you are enabling the panel on a click of a button) :
This issue has been added to PITS issues. You can follow the PITS Issue by its ID:
4466
Thank you for bringing our attention to this issue. Your
Telerik points have been updated.
Let me know if this helped you. Should you need further help, do not hesitate to contact us.
Best wishes,
Ivan Todorov
the Telerik team
Q3’10 SP1 of RadControls for WinForms is available for
download; also available is the Q1'11
Roadmap for Telerik Windows Forms controls.