Random error on network printer

Nt4.0 server,sp6,hp jet admin,114 users,4 hp5 printers with unique IP addresses.
Out of “nowhere” and at random intervals one HP printer is printing dozens of sheets of paper (watermarked bond) with AscII characters across the top two lines. Have traced print services with the event viewer with no success and have looked for errant print requests locally on the Win98 clients. On a long overnight I have shut down all systems except server and printer in question. Then waited. The printer beginsspooling out these sheets but the server does not indicate that anything is occuring. Any ideas?? Anyone! Printer outputs 1500-2000 pages daily with no problems from multiple local and remote hosts. Many Thanks