Thanks for contacting us and for your question.
I have investigated the case and was able to reproduce the undesired behavior. I would like to inform you that the issue is already addressed and the fix for it will be available in the upcoming Q1 2010 SP2 we plan to release soon.
For the time being, you can use the following workaround:
.radTitleBar1.TitleBarElement.SystemButtons.Visibility = Telerik.WinControls.ElementVisibility.Collapsed;
This will simply hide the layout panel that holds the system buttons making them also invisible.
I hope this helps.
Do not hesitate to get back to us in case you have further questions or need assistance.
the Telerik team
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