Bowhunter - A question. Does the plug begin to unscrew then tighten up? If so, you need to unscrew until it gets tight, then screw back in and retry. I know its a pain. My Genesis is the same way.
You can also try applying a layer of teflon tape, then the anti sieze lube prior to reinstalling.
Also, be sure that the breach is clean. Really clean. I remove my barrel from the action and after I clean my barrel, Ispray this area again with windex with amonia and scrub it with a chamber/breach brush then flush with hot water. Run some dry patches down, then a patchwith alcohol, then a light coat of gun oil.

Maybe not but my suspicion is that you may still have some fouling on thethreads when re-installing the breach plug.