Unable to change EVERYBODY values in permissions

I appologize that I can't supply all of my information, but I am away from home and I can't ssh into my server from my office.

I am trying to change the permissions of a gallery to not allow people to view full size images. It appears that any of the fields that have EVERYBODY as the default value are not changeable. Whether I try removing the value EVERYBODY or try adding the value NOBODY, it never takes the change. It also doesn't allow me to remove any users I add to the NOBODY fields. It does not return any error.

If this is a known bug, where can I go to manually change this value? I tried changing the value in album.dat, but that did not change it.

Thanks!

Gallery version 1.5.3:
Webserver Apache:
Database MySql:
Operating system Linux (Clarkconnect 2.6.9-42):
Browser Firefox 1.5.0.8: