Applications do not find CUPS printer

[Scott Moss]

I am running FC5 on an X86_64 workstation.  The printer configuration
gui (System>Administration>Printing) finds our LAN printer (HP4100) and,
from the Test menu, successfully sends both the CUPS test page and the
A4 PostScript test page to the printer.  However, no application
recognises the LAN printer -- not Office, not Gimp, not any of the pdf
viewers, etc.  I have disabled SELinux for all of the cups and cupsd
daemons, servers, etc.  I even tried disabling both SELinux and the
firewall.  Everything is up-to-date from the Red Hat, Livna and
FreshRPMs repos.

I'd be very grateful for any suggestions about the problem.

Thanks in advance,
Scott