Hmmm that made me think - I wonder what would happen if I ran Leo without EFI? The last time I did this was with 10.5.1 rev1 and I can't recall whether or not I had any performance problems. If I can clear a spare drive, maybe I can give it a try with a standard MBR Leo 10.5.2 rev1 install. I think I'd have to take out my 8800GT, though, since it needs the graphics update to run properly (and updates are out of the question without EFI, right?). I can always swap it out for my old card, I guess. Does this sound like it would do any good as a test for our problems, or just a waste of time?