It really sucks too, because I needed that outer barrel from the upper that I ordered. I somehow managed to get a suppressor stuck on mine at the CQB length. I don't know if it seized up, or what. I don't think it cross threaded, because it went on normally. The only way to get it off was with vice grips, and it took the threads with it. I guess I'm SOL until Wetti gets one of the parts centers up and running.
EDIT-
But on a lighter note, my WE MEU with a neoprene flat washer on the guide has pumped out about 500 rounds, with no sign of any wear and tear whatsoever. No breakage.