File size of print jobs increase

I am having a problem on multiple computers. It seems to only affect Win98 machines. The print server is running NT 4.0 SP6a. The types of printers affected are Lexmark SC1275 and IBM Infoprint 20. The problem is that when a print job is sent to the queue, the size of the job increases and the printer prints multiple copies of the job. It usually takes a reboot of the Win98 machines to clear the job.

Thanks in Advance

Paul