WIN2K IP Issue

Our 6 user WIN2K network has worked fine for about a month. All of a sudden print servers could not be printed to. We found we could not ping from the server to any device on the network. However, devices could ping to one another and back to theserver. We configured ip ports to the printservers and can print. NBSTAT reports com is established, loop back functions but ip only works one way. What is wrong with this picture?