If any of you have had problems with OS X crashing a lot (perhaps even during installation) on PowerBook Lombards, you are not alone. Lots of people have had this problem. It appears to be caused by the presence of RAM modules beyond the base 64MB. If you have a RAM upgrade in your top slot, OS X should work fine after you remove it.
It is unclear what is causing this problem, at first people said it was due to tighter memory tolerances, but then reports came in about even apple RAM upgrades causing the crash. Now it seems like it may be a lingering hardware bug that wasn't revealed by previous OS's. You can read lots more about this on the MacFixIt Forums in this thread.
Apple does not have a fix for this yet, in fact they appear to be denying that it is a problem, so I encourage anyone else experiencing this bug to fill out a bug report form.
Patri Friedman (patriNOSPAM@izzy.com)
Mac OS X Hints
http://hints.macworld.com/article.php?story=20010409212137745