IMac freezes when changing the screen saver

Question

Hi all:
I originally posted this in the "Using Mac OS X" forum (iMac freezes when changing the screen saver, but thought I'd post here as well since the issue arises on a freshly installed OS.
We've got three 350MHz slot-loading G3 iMacs (with 512MB RAM) which we're planning to use for basic word processing. The install of Panther (10.3.5 from black retail cds with 10-seat volume license) went fine on the first two. Ran the updates to 10.3.9, installed MS Office 2004, everything working great (they're a little slow, but after all, they are only 350 MHz).
On the third, the first problem we noticed was the computer would lock up whenever we changed the screen saver from the default (Flurry; Computer Name also works). It continues to do so even after: repair permissions; repair disk; Disk Warrior; reset pram; reset nvram; reset pmu; change RAM; change hard drive; erase hard drive; write zeros to hard drive; reinstall with different set of retail CDs; trash preferences, and delete cache files. (If there's anything I've left out, it's in the other thread).
Now we've noticed that we can't create any new user accounts. We've thought about putting this one in production, just warning the user that they can't change the screen saver, but god only knows what will turn up next.
I'm starting to think it's a logic board issue, but could it be that selective? And would you see the same problem with another hard drive and different install discs? Am I missing something?
BTW, there's a crash log with the other thread.
Andrew
Dual 2.0 GHz G5   Mac OS X (10.3.9)  

Answer 1

I'm going to mark this one as answered.
I removed the hard drive from the iMac, and put it into another 350 MHz iMac, and everything works great. I can select any screen saver without having it freeze, create new accounts, whatever my little heart desires.
In checking the history of the problem iMac, there was an assortment of problems with booting (both from the hard drive and from the CD-ROM drive) which were never satisfactorily resolved. The problems just seemed to go away after sitting unplugged for a few days, as much as for anything we actually did to it.
Now we just have to decide whether it's worth fixing, or using it somewhere in a non-critical role with OS 9 installed.
Cheers,
Andrew