Print Spooler Issue

I have a user that sends a monthly print job from Excel to a networked HP color printer. Nearly every time this job is sent, the spooler hangs and I am forced to reboot the server to restart the service. After the server comes back up, the print jobprints again. This is not an especially large job (10-12 copies or so of 10-12 pages). I do have some drive space issues with the c:\ of the print server (low). I am using Windows NT 4.0 SP 6a. Any idea why this is occurring? Thanks!