Yes, this is known issue for the current Q1 2008 SP1 version. Unfortunately, since we are in the final stage of the development process for upcoming Q2 2008 release, this issue most probably will be postponed for one of our future versions.
For the time being I can suggest a workaround which is using the reflection approach. It will improve the flickering behavior of the RadForm's title bar. Please note, that this workaround may lead to issues in some situations concerning the RadForm's Non Client area (the titlebar). I am attaching a sample project to demonstrate it.
If you have additional questions, feel free to contact me.
the Telerik team