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.