On occasions a print job does not come out on a printer. lpstat -u shows the jobs waiting to be printed and lpstat -t shows the printer as disabled with a time out of some sort.

cupsenable enables the printer and the job comes out on the printer.

What could be causing the printer to become disabled and is there a setting that can be modified to avoid this happening in the future?

What is your distribution?

I am assuming CUPS is running.

What do the logs say?

You could have the wrong driver installed for the printer. The fact you eventually get a completed print job probably indicates the connection is good.

I did have to restart CUPS on a Red Hat system, because it did not like finding a published printer on another system. Given CUPS had to be restarted on an important production system, I unpublished the printers on the offending system, and all is now well.

Red Hat Enterprise 4.5
CUPS is running
Message: Remote host did not respond with command status byte after 300 seconds!

Red hat enterprise has many HP drivers but it does not have one for the HP LJ 2420. I was using generic PCL 5e and just changed it to generic PCL 6. That's how our windows server has it defined.

The printer is connected to a Jet Direct box and is defined in two other servers: Windows 2003 and SCO Unix.

We'll see if changing the driver helps, if not I'll remove the printer from the other boxes and post the results.

A package for HP that works well is : printconf
It configures the hp itself. The LJ could be got from the linuxprinting

I have found I must use the CUPS interface or command line on RH EL systems. This is especially true for older print servers that do not default to port 9100. Using Red Hat's configuration results in the printers using those print servers to have their port numbers change to 9100. Stick with CUPS or the HP configuration mentioned.