Mac OS X.1 is a PITA when it comes to privileges. I would back up the files and upgrade to at least Mac OS X.2 (Jaguar) which has much better permissions.
If not, then go into Disk Utility (your HD/applications/utilities) and then to Disk Utility (it may be called something else in OS X.1). Then repair permissions and see if that works. Not sure if thats available in OS X.1