Screen Jitters on Power mac g5 dual 2.5ghz

[powsbmx]

I have a power mac g5 dual 2.5ghz. I recently bought a new AtI radeon 9800 pro 256mb. Installed it and it worked fine up until a couple of days ago. So i put my old video card back in, the ATI Radeon 9600 XT and my screen jitters back in fourth and wont stop. I don't know what to do, tried the zoom it was off. Tried running disk permissions and that didn't work. So i need your guy's help please.

[geoffreak]

Have you checked to make sure your eyesight isn't at fault? ;)

Maybe both cards are faulty or a logic board needs replacement?

[powsbmx]

it all work just fine until i switch the cards. so i don't know