Blank Screen in Full Screen Mode - 8500GT

[Em Gee]

Anyone have any thoughts on why my screen would go blank when viewing movies in Full Screen Mode? Picture never drops when viewing in a reduced window.

This happens with regular def and high def dvds.
This happens with both Windows Media Player 10 and Power DVD Ultra

I recently upgraded to this card so that I could play HD movies. My previous card (6600GT) worked flawlessly for standard DVD's and HD television.

I have followed 3 steps from xfx tech support, but it hasn't helped.
Run Driver Cleaner - Reinstalled Nvidia drivers
Enabled VGA Mode in the "safe mode" startup area
Installed the K Lite Codec Pack.

If someone from Tech support reads this, my ticket number is 137644

Thanks for your help.

System:
Power Supply: Silverstone 400W ATX PSU
Memory: 1 GB Dual Channel DDR PC-3200 at 400MHz 2x1024MB
Mother Board: GIGABYTE GA-K8N Socket 939 NVIDIA nForce4 Ultra Primary
Processor: AMD Athlon™ 64 X2 3800+
Operating System: Windows XP Professional SP2
Video Card: XFX 8500GT

[xfxsupport]

Are you viewing on a dual monitor set up (movie on one monior/tv)? Is type of monitor are you using?

[Em Gee]

Nope. Single monitor. Hitachi 42" 42HDT52A

Connected via DVI to HDMI cable.

One thing that I did notice is that before I installed this new card, the monitor would always identify the source as DVI.

With the new card installed, it identifies the source as DVI at the beginning of the boot process, but then towards the end of the boot process it says HDMI. Not sure if that has anything to do with it.

Thanks for your help.