exiting WMC full screen - video turns to crap/blurry

I have a weird issue where my screen will get all light colored and just really crappy quality - blurry. I'm not sure if it is Windows, Nvidia, the HDMI cable, my monitor or what. I apologize if this is the wrong forum.

This usually happens coming out of full screen from Windows Media Center, but sometimes after a reboot.

I can turn off my tv (Sony Bravia - 52" LCD - KDL-52W4100) and turn it back on then the problem is fixed. Sometimes I can go full screen and back out again and that will fix it.

I have HDMI connection - Windows 7100 - I have the latst Nvidia drivers 186.. - I have tried a different HDMI cable also

Here is the rest of the build.

Intel Pentium E5200 Wolfdale 2.5GHz LGA 775 65W Dual-Core Processor
GIGABYTE GA-E7AUM-DS2H LGA 775 NVIDIA GeForce 9400 HDMI Micro ATX Intel Motherboard
A-DATA 4GB (4 x 1GB) 240-Pin DDR2 SDRAM DDR2 800 (PC2 6400)
Hauppauge WinTV-HVR-2250 Media Center Kit Dual TV Tuner
Western Digital Caviar Black WD1001FALS 1TB 7200 RPM SATA 3.0Gb/s

Anyone else have this problem - or perhaps point me in the right direction?

ok - I think I fixed it. It's been a few hours now and all is well.

Nvidia was set to 60 Hertz
Sony was 60
but Windows was 59.

Screen Resolution - Advanced Settings - changed that to 60 and so far all is well.

Hope this helps someone else.