[SunHELP] device /dev/null printer will stop accepting requests

[sunhelp at sunhelp.org]

I created a printer called noprint which points to /dev/null and uses the
HPLJ4 driver so that it will understand certain HP options that get passed
to it, thus sending the printing to /dev/null ~without errors~.
 
configuration
~~~~~~~~~
Banner: optional
Content types: simple
Device: /dev/null
Interface: /usr/lib/lp/model/net_lj4x
Printer type: unknown
Modules: 
Options: 

This configuration works fine for a few days. This is required by an
application that insists on printing to a printer when it runs a particular
job... Anyways, the printer stops accepting print requests and then I go in
as root and run "accept noprint" and all is fine.  I haven't caught any
errors in syslog nor does root have mail regarding this.

Any ideas?