I was using a Jetdirect print server (parallel) to an HP 960c printer. I got Event ID 6161 when printing with a non-admin user and the spooled docuements said Error. The fix was to set the Jetdirect TCP/IP port on the server as the IP address of the Jetdirect, NOT THE HOSTNAME.
Also, quick check, give full control to c:\windows\system32\spool directory.