I feel silly for asking this, but my brother has an old iMac G4 (700 mhz, combo) that he just got 256 more ram for (for a total of 512). But we can't install it... Now, I've installed RAM in plenty of macs, but this just doesn't fit. It's definitely the right kind of RAM, bought retail and double checked, is clearly the right size, etc. But it won't quite slide in right, and the computer doesn't recognize it as being installed. Is there something wrong with the RAM slots on these imacs? Isn't the RAM supposed to just pop in no problem? I really can't figure this out. It seems really stupid, but the RAM just won't go in right. thanks!