printer dilemma

HI
I have a small home network and the setup is cable modem to SMC router 7004br with HP Lasetjet 2100 connected to the printer port, I have 3 PC’s on the lan ONE with 98se TWO win 2000 pro THREE win xp pro. All ok till now when out of the blue theprinter will not respond when trying to print from the XP machine ok on the other two. Any thoughts please.
thank you

john