I haven't tried it on 10.5 Server yet but under 10.3/4 I've always gotten good results from *Disk Inventory X* especially when launched using
Pseudo to make sure you have root permissions for the disk check. One nice thing is it gives a graphical feedback which makes it easy to spot the culprit if something is taking a bunch of space.
HTH,
=Tod
PS I just wanted to add this reminds me of the first time I really used DIX to good effect. I had a user who had inadvertently ended up with his drive becoming the target of his Retrospect back-up process so it was backing itself up to itself. He couldn't see the hidden Retrospect volume but he knew his drive space was magically disappearing. Hmmm...
http://www.derlien.com/
http://personalpages.tds.net/~brian_hill/pseudo.html
Message was edited by: Tod Kuykendall