I have one of the new 20" iMacs, and only got the standard 1 GB of RAM. Well I purchased the following: tried it in my iMac, and the machines was stuck in a constant reboot loop. I would get the startup sound, the apple on the center of the screen and then an instant reboot. I removed this RAM, keeping only the stock RAM in there, and the machine booted fine. Removed the stock factory RAM, and just tried booting the machine with the extra RAM I bought, and nothing happened, the machine wouldn't do anything, except I could hear the optical drive spinning. I did push the RAM in as far as it would go, but I never did get the "snap" sound that the factory RAM would make when pushing it into place. I've since returned the RAM and got my money back, but I still want to upgrade it. I only need a 1 GB stick. What would people recommend? Where should I get it?