Profile Question

When I try to update my signture on my forum it gives me a 403 Forbidden error page. All the features in the profile work.

You don't have permission to access /profile.php on this server.

It only does it on the 'Profile' - 'Personality' page. The server mod is set for 644. And I tried uploading a fresh copy of profile.php.

Thanks in advance for your help.