I'm using a 22" Vizio LCD HDTV as my monitor for my new desktop atm. It works great until I try to play a game on my computer. The game will run fine for 2-3 minutes before the image freezes and lines slowly distort it from top to bottom. I used this TV as my monitor for my laptop for a while and had this happen when I'd try to watch a DVD, but not when I'd play games. Both setups were connected with and HDMI cable.
The main reason I'm confused by this problem (with the desktop at least) is the fact that it didn't happen the first night I played Fallout 3 on the desktop.