If there's network printers involved, it's sometimes good to stop the Print Spooler Service manually. Start>>Run>>cmd>>net stop spooler (or you can stop it from the services console in control panel)

Then navigate to c:\windows\system32\spool\printers

in there there may be a few print jobs that are gumming up the spool delete everything in that folder.

then restart the spooler service

net start spooler

See if it remains stable