Spent several hours this morning trying to resolve this one. Apache 1.3.3 with RH 5.2 does not allow access to users directories. Any attempt to access the public_html directories for any user results in the "Forbidden" page being returned. Nothing on the Apache "help" site is any help. Did RH do something since Apache is not installed in its default directories? Wasted a LOT of time trying to resolve this. It was NOT a problem with the RH 5.0 release.
what's the permission on the .public_html directories, and the user's home directories?
what is the error in /var/log/httpd/error_log right after trying to access the directory? This will almost surely tell you the real problem.