I have a test application using the Lync 2010 SDK in full UI suppressed mode. When the video is started by either party, on some computers the VideoWindow won't display in the panel that I provide the handle for. It instead is displayed on the upper left hand corner of the screen. This also happens with the sample applications provided (I am also using the example code to display the VideoWindow on a panel).
I did notice on machines running windows XP the video consistently is display in the proper location. Only on my Windows 7 test machines do I have an issue with the video location. If I don't mess with the window style and allow the border, the window title says "ActiveMovie Window".