Thanks! I downloaded and installed the 08/17/05 security update and the 08/29/05 safari update. I installed the security update then the safari update and everything worked :)

Thank you all for your help in solving my first mac related crisis, my dev computer is now working again without me having to go out and purchase anything. I am definatly going to pick up a copy of the OS 10.3 disks when they drop in a price a little more, just to have them on hand as you guys recommended.

In the end I suspect it was simply a corrupted security update from the auto-downloader.