I can ad something here. I was one of the first to update to 10.3.9 on a Powerbook while in a hotel room. I did everything wrong, did not backup first, did not logout and back in and did not fix permissions first. Anyway...it completely sank my PB (17", 1Ghz). Upon returning home (today), I updates a 800Mhz Ibook (no problem), reinstalled my 17"PB and reloaded everything (took most of a day to get all my settings back the way I like them) THIS TIME, the update worked fine (but had my trusty Backup just in case)..but for those curious, I restored the user and Application and Library directory's (I did not restore prefs, just in case). So it had nothing to do with the software I have loaded (since all my computers are the same pretty much). I have yet to update my 2.5Ghz or my other 17" PB. But this time the update has worked fine. But it IS 4 days later.