network problem?

Hi,
I have a windows nt 4.0 server(pdc).
It is my file and print server. I have a problem w/the network printers on this server. They are intermitely working. I’m able to ping other servers on the network but when I try to ping a printer it sometimes works. People are able to access there folders and files with no problems. I checked the switch there are no errors on the port. Any help would be appreciated.