Thank you for contacting us. I noted that you are using an old version of RadControls for WinForms. We addressed a similar issue in our latest release - Q1 2011 and I recommend that you try it. If the issue continues to appear, please answer the following questions:
1. Which is the version of your operating system and is it 32 or 64 bit.
2. Have you changed the DPI settings of your monitor.
Thank you in advance for your cooperation. I am looking forward to your reply.
All the best,
the Telerik team