Odd behavior when starting Media Center

I have a homegrown HTPC computer with a fresh install of Windows 7 Home Premeium connected to a Sharp 52" 1080p HDTV via a DVI-HDMI cable. The motherboard is an Asus M2NPV-VM with a onboard NVidia GeForce 6150. When booting into the desktop the display is fine (1920 X 1080, 60Hz), but when Media Center is started maximized there is only a blank screen with audio being fine. If Media Center is started in windowed mode I can see the Media Center display or during ALT+TAB changes I can see it when it's icon in the task switcher is selected. When the ALT key is relased I get a blank screen. I have updated to the most recent NVidia driver and also run through the Media Center display configuration utility. Neither had any effect on this behavior. Any suggestion would be appreciated. Thankyou.

Update 12/29/09: Found that if I set the resolution of my desktop to 1600 X 900 I can then start (and see) the Media Center menu screen. Of course, this is unacceptable since the TV's resolution is 1920X1080...

Hi intruder196 & welcome :)
Sorry for the late response!
See this thread;
maybe try starting up MC with the correct resolution, and try widescreenmode, nochrome, mediamode (as seen in the tut). It's a long shot but worth trying IMO. :)