pending 'stuck' print jobs don't appear in Mac 10.6 interface but appear in CUPS web tool

[Brian]

We use a product called Equitrac to manage/authenticate print jobs from the OSX 10.6 workstation through to our Windows print server. When a print queue gets stuck on the 10.6 workstation the jobs do not appear within the native Mac printing interface, you have to log into the local CUPS web server to see the jobs and manage them. Here is a screen shot.

http://fileserver.wheatonma.edu/gibson_brian/print_queue_paused.png

Any suggestions on why this is happening?