JSI Tip 0566 - LPR print job spools in an endless loop or the jobs hang?

Check the Idle-timeout using the printers control panel or via a telnet session. The default is 90 seconds. If the value is set too low, the subject behavior will occur.

Check your JetDirect documentation for how to make the change. If the setting is too low, you may not be able to use a telnet session as it will time out before you can type the commands.