Shared printer reboots PC

I am the Administrator for a small company w/5 windows 98 computers and 2 Windows NT 4.0 computers. one of the Windows 98 pc’s has a shared HP Laserjet 4L printer – everyone can print to it ok, but at times when 2 of the 5 windows 98 pc’s sends a print job it will reboot the pc that is sharing the printer – I have tried setting the spool settings to print directly to printer and set it to RAW – fixed it for awhile but then started happening again – I ran a scandisk on all the pc’s and the problem continues – I have also tried reinstalling the printer driver – still happening – checked for loose or broken cables but all seemed ok – any ideas?