This bug has been copied from bug #565823 and has been proposed to be backported to 5.5 z-stream (EUS).
Technical note added. If any revisions are required, please edit the "Technical Notes" field accordingly. All revisions will be proofread by the Engineering Content Services team. New Contents: When the class members were changed, /etc/cups/classes.conf was not always updated accordingly. This issue has been resolved, and the configuration file is now always updated as expected.
An advisory has been issued which should help the problem described in this bug report. This report is therefore being closed with a resolution of ERRATA. For more information on therefore solution and/or where to find the updated files, please follow the link below. You may reopen this bug report if the solution does not work for you. http://rhn.redhat.com/errata/RHBA-2010-0614.html