Hi,
Sorry, I misread your original post as saying 'you could still see the back/forward buttons but not the address bar'
Based on the things you've tried so far, one quick test you can do to help narrow down things is to try Safari in another user account. This will help us to know whether your problem is local to your account or system wide. If you don't have another account you can use System Preferences -> Accounts -> \[+\] to create a test one (and \[-\] to remove it if needed)
If the other account has the same problem, try downloading the 10.4.11 combo update (your original post mentioned 10.4.11 in your profile) from the Downloads link at the top of the page and then using [Pacifist|www.charlessoft.com] to extract the Safari package from the update.
After that has been installed, download the Security Update 2007-009 v1.1 and re-run that to update Safari to the latest version.
Let us know how you get on.