Hung printer queue's

[Bill Lasher]

We have a room full of Personal IRIS's on a network, with several plotters and
printers.  All machines are set up to send their plot or print files to the
appropriate device over the network.  The output devices are plugged into the
serial or parallel port of one of the machines.  Most of the time, everything
works fine, but every once in awhile, the queue gets hung.  If we lpstat on the
machine that created the file, it shows it as currently being printed, but
nothing is coming out of the printer or plotter.  Any jobs sent after that just
sit there.  If we cancel the job that hung, the queue is freed up and
everything works fine for awhile.  It doesn't appear to be a specific file; if
a file gets hung and we cancel it, then re-submit the same job, it works fine.
We have contacted the SGI hotline, but they don't yet know what the problem is,
however, they did say that someone else had reported it.  Anyone else having
this problem; or any ideas as to what might be causing it?

Many thanks,

Bill Lasher