Get rid of all things Microsoft and OS X won't lock up.... For some reason, the only apps that ever cause my powerbook to become unresponsive are Excel, Word, Powerpoint and IE. Even then its quite rare. Adobe apps are slow but quit graciously. MIcrosoft apps hang on by their cloven hooves......
As far as I can tell, it's Samba that's causing Mac OS X (or, rather, certain applications as well as the Finder) to hang for several minutes. It seems that if a Samba share disappears (before it's unmounted), then Mac OS X keeps looking and looking and looking for it before giving up.
Of course, it'll turn around and do the exact same thing moments later (because, hey, it could have magically re-appeared).
Mine doesn't seem to lock up...at least the spinning multi-colored ball goes away eventually ...
But the one thing that really has me bugged is that I have two CDRW's...one built-in (aftermarket A-open) and one external (Iomega) and BOTH are listed as "not supported for burning" in the system profiler!
Thank god I've still got the trusty ol Pismo on 9.2.2 and EVERYTHING works on that one!
I only have problems when Samba is involved, which is thankfully basically never on my home machine.
Also have issues when using this fun little screen saver called SaveHollyWood, which works just fine but if you let it run for more than half an hour at time it takes a few minutes to recover. It's got some serious issues.
macnutt, do you have Toast Titanium? It works much better for burning than the finder. MUCH better.