Panasonic Plasma & PC Gaming. Help!

[Maul]

I have a Panasonic Plasma HDTV (TH-37PX50U). I have connected my PC with component cables using an adapter that came with my video card (geforce 7800GT). My prblem is... when I fire up a PC game I'm only getting a small picture in the center of the screen . I don't have this issue with Half-Life 2 for some reason. This also happens when I try to put the windows media player in fullscreen mode. I am using the nvidia tweak for 1080i mode. I used the keystone feature to position my browser correctly.
What can I do to get my PC games to display correctly???
I have also tried a dvi to hdmi cable but the component seems to work better.

 

[GJohn]

I so the same thing but never had that problem..but some movies it gets picture in the center of the screen because i think its not a wide screen movies

and try to play with settings on your plasma

 

[Maul]

When I start a game I only get a very small picture in the center, not even fullscreen. Probably 6-7 inch squared. Black around the small picture. Guess I'll have to be XB360 exclusive now.