After install cups and remove cups, my redhat 7.3 (2.4.20) never print 
again. The lpq will show:

Printer: pr3@dhcp212
  Queue: no printable jobs in queue
  Server: no server active
  Status: job 'nick@dhcp212+631' removed at 11:32:57.687
  Rank   Owner/ID                  Class Job Files                 Size Time
done   nick@dhcp210+680             A   680 (STDIN)             191263 
20:59:07

But windows machine print well.

How to trace this problem? I tried to change to unix print to jetdirect, 
both doesn't work (it works before).