I recently purchased an ATI 9800 Pro Mac Edition 128MB card. I downloaded the ATI Displays software then followed the instructions of installing the card into my G5. But, when installed, nothing comes up on the screen. I've plugged into the VGA and DVI ports (using a DVI to VGA adapter) and nothing shows up. I read that resetting the PRAM may help but couldn't get that to work at all. I can reinstall my old card and get the display to work. Any suggestions?