I'd bet that it's not particularly likely that it's wholly an OS problem; there are probably some other contributing factors. USB devices, kernel extensions (Norton is *particularly* bad), etc. Have either of you done an archive and install, and not installed any new items that require kernel extensions, or otherwise practice black magic? I'd recommend removing ALL third-party devices before doing this; printers, RAM, etc. etc. etc., until you have run your computer for long enough to determine whether the problem is still present or not. Kim Gammelgaard <kgani at mac.com> writes: > I am having the same kinds of trouble with both my iMac(17") and my > AlBook(15") for some time(My iMac locked up twice within the past 24 > hours > and my PB once, but failed to boot at all for a while. Only the 5th > restart > made it work...). > > The problem is also that there are no logs being written when the > lock-ups > appear, so there is no clue how to figure out what goes wrong. There > is a > lengthy thread at arstechnica at the moment: > > <http://episteme.arstechnica.com/eve/ubb.x? > a=tpc&s=50009562&f=8300945231&m=1 > 90005950121> > > I am afraid that the problem is so low-level, that it won't be > addressed > before 10.4. I'd wish it would though. > > I still love my Macs, though ;-)