Wow! I read your post and thought of how the tail cap on my Surefire E2D recently started making a rattling noise. The problem wasn't a big deal, the light still worked. I live pretty close to their headquarters, but haven't had the time to jet up the 405 lately. I called them up and they're sending me a replacement part after only about a 1 minute call. I bet I receive the part before my match on Saturday morning. We are shooting 1 stage in pitch black and 1 in low light - don't know about the other 2 stages. I'm in the market for another tactical light and will definitely be getting another Surefire. My wife wants one too.