On my Mac Pro 4-core 3ghz, I get different About-This-Mac screens and profiles on different boot-ups. I do have 8 gig of Crucial RAM installed in addition to the 1 gig of Apple RAM the machine came with. I haven't quite figured out what's happening to that particular 2 gig RAM. Seems to disappear randomly. I do have Boot Camp set up and running Windows XP, no Parallels on this machine. The machine runs perfectly. Never had a crash, never had a kernel panic. The problem is always in DIMM 1 of Riser A. Any idea what's happening here?