I searched here and googled this and can't seem to find any answer anywhere so hopefully someone in here knows. I have a three iMac G4s a 15" 800Mhz, a 17" 1Ghz, and 17" 1.25Ghz. The 1.25 had one stick of 512MB RAM on the inside slot (I can't remember the technical name; it's the one that requires taking more than the plate off to get to) so I decided to take a 256MB stick out of the bottom of the 1Ghz and place it in the 1.25Ghz to speed it up a little. Well, it doesn't read it. I know it works (because it works in the other one) and I know it's seated correctly, so what does this mean? Is there any way to test to see if the slot doesn't work? I know they both take the same kind of RAM (according to OWC at least). I was going to upgrade both to 2GB but now I'm leery to order any until I know there isn't some big issue with the 1.25Ghz one.