I just purchased the 20 inch Cinema Display (clear enclosure). When my G4 tower is starting up the display is at 640x480 - the apple logo is huge and stretched. But when it's done starting up it's back to 1680x1050. How do I get this corrected? I reset the PRAM and NVRAM. That didn't help. It's just annoying. Prior to this new screen I had a 15 inch crt. Is there a solution to this? Thanks!