Recent switcher here. Picked up a G4 17" iMac, and LOVE it. It could use a RAM upgrade, though. For some reason, the internal RAM isn't being used. The System Profiler claims the spot is empty. The easy to get to one on the bottom seems to be working fine, but it's a lowly little 256. I'd like to upgrade to its full potential, but am concerned the problem with the internal might be a logic board problem. Any way to tell? Should I just get a 2gb stick for the known-good slot? Where can I get one for less than the $87.99 Crucial wants for a 512mb?