Can you please tell me which Map widget are you using (are you talking about the Silverlight Controls Map widget, or something different?) Also, do you mind specifying how exactly are you using this control - do you have it implemented in a user control that's used inside Sitefinity, or you have some other application scenario? Any additional information that might help me reproduce this issue and inspect it would be welcome. Thanks in advance.
All the best,
the Telerik team