To Reproduce:
This actually happens wherever the window is placed (once the window has been dragged), but it is particularly noticeable in the scenario described above.
I notice it also occurs in V8.1
Thanks,
Jon.
This appears to be a bug in the XamRibbonWindow. I submitted the issue but you should contact the support group so you can be notified when the fix is available - http://ko.infragistics.com/gethelp/default.aspx. Please be sure to mention issue #BR34679 so they can associate your report with the submitted issue.