NT 4.0 and Printers

We have a Dell server, running Windows NT 4.0 sp 6a, 2 PII 400 Mhz, 256MB Ram. We have been having problems with our Printers, the spooler seems to jam up, and we have to stop and restart the spooler service to get the printers to restart. We havenow added more printers today to our network, and the printers are stopping quite a bit. Does anyone know of any problems/limitations with Windows NT 4.0 server. Our printers are setup using TCP/IP Printing with LPR. Thank you.