31mm Nagler Loose Lens!

I was noticing an increased amount of coma and astigmatism in my 31 Nagler and today while cleaning it I noticed that it rattled while moving it arround. I unscrewed the barrel and found the inner barrel lens ring had loosened and the lens was moving around. I tighten the ring so that it was held from rattling without overtightening it and causing it to pinch. There was also a bit of black paint that had flaked off the inside on onto the lens, which blew off easily enough.
I am not sure this happens often, but if you notice some degradation in performance on your Nagle, check to see if you are having the same problem.
Floyd