Serious PS3 issue w/demos

[Joe Cain]

Hi folks, newbie here. Got my PS3 about 2 weeks ago, loving it...

Except last night it kinda started freaking me out. I don't own any PS3 games yet---been using it for watching films, playing my PS2 games, and enjoying a few demos from the online PS store (NCAA Football '08, Resistance, NFL 2K8). Yesterday I downloaded a few more: GRAW, Dirt, and a couple more I can't recall. After installing GRAW and trying to play it, the weirdest thing happened. The "Playstation 3" logo flashed across the screen looking fine, but upon entering the gameplay menu the entire screen started flickering in this strange shade of yellow-green: it was like looking at the TV through night vision goggles. Actually I thought for a moment it might be by design---it's a Tom Clancy game, after all---but the same thing happens with ALL my demos now. PS2 games, DVD & Blu-Ray playback are all unaffected.

Is there the possibility that installing one of the demos could have monkeyed with my settings somehow? TIA for any advice you have to offer.