printer suddenly disappeared

[Buz Davis <buzdavis earthlink net>]

I have a locally connected (dev/lp0) samsung laser printer that I have
been using for a couple of years now.  Suddenly this evening I am unable
to print to it from my Linux box (Red Hat 9).

on attempting to print the file 'pthis' I get errors:

lpr pthis
lpr error - no default destination available
lpr -P printer pthis
lpr error - unable to print file:  server-error-service-unavailable

If I go into Gnome/system tools/print manager I get "No printers found.
Run the printer configuration tool ?".  On clicking OK and giving the 
root password the printer configuration appears, and it correctly lists 
the printer and notes that it is the default.  But it gives the 
"service-unavailable" message when I attempt to print a test page.

I have tried disconnecting the printer cable and letting Kudzu remove 
the configuration, then connecting it and rebooting, and Kudzu finds and 
configures it (so it says).  Then on entering the Gnome configuration 
tool I find that the data are still there. (I even tried deleting them 
and recreating).  None of this has helped.

Any ideas would be appreciated.