Long story short. GF has a Mac G5 that was having start up problems and freezing. I noiced that when booting up there is a led on the power button that would flash 3 times. I looked this up on the web and it is an indication of bad memory. I bought the exact same spec memory at a computer store. Put it in and it works on first boot up. Then the same issues come back. Now it seems worse. Can't even get the mac to boot up. Push power button, fans come on but no sound and then the led starts flashing. I've searched a lot on the net and I find it hard to believe that macs need some kind of super special ram. Ram is ram. So what else do I need to check? Thanks....