I recently received a black MacBook for my birthday. It was purchased from someone who purchased it in April, and I'm under the impression that it was not defective when purchased and that if there is a defect, it is not in the hardware. When I got it, I formatted it and transferred all of my programs and stuff over from my old iBook G4. It worked alright for a little while, then began apparently locking up. When it locks up, any programs I click will bounce indefinitely and not open. Anything I attempt to force quit usually hangs, and if I force quit something and it does appear to close, the dock still says it's open. It seems as though something's tying up all of the system's RAM. Thinking that maybe some non-universal binary programs had been brought over from my old machine, I did another install of OS X over the first one, this time an archive install, and had all of the basic applications (Safari, etc.) replaced with things I know are universal binary. It's seemed to have less problems since, but it just crashed a moment ago for unknown reasons. I haven't been able to identify a particular program that's causing this, although I'm fairly sure the few programs I'm running right now are "clean". One of the suspects appears to be Mail, which seems unlikely considering that I'm fairly sure this install replaced it, too. Have any of you seen or heard of a problem similar to this? Do any of you have any idea what could be/is causing this, and what could be done about it? I've still got a good warranty, so I'm not too worried about that, I just wanted to be sure I couldn't remedy the problem myself before I went through the trouble of bringing it in and basically wasted someone's time Thanks in advance.