quickbeam: i agree....i was definitely quite dissapointed that the E2e and my M2 leaked on me. anyway, surefire expects their lights to be waterproof as well, so if yours leaks they will replace the offending part without asking any questions.
so far the only problems with leaking surefires are associated with either the E2e O-ring squeeze problem or an improperly wet-glued pyrex lens bezel. the O-ring squeeze problem is due to a design flaw, which currently has a fix which surefire will provide you with free of charge.
sealing the pyrex bezels with wet glue is a less straightforward way as opposed to using an O-ring like other cheaper but waterproof lights, but its definitely a more effective method if done correctly. the advantage of a wet-glued bezel is that its maintenance free, in that you don't have to maintain the O-ring and make sure it doesn't dry out, etc. if you've been to an aquatic zoo, you'll see that the tanks which hold in tons of water are sealed in a similar way, and they don't leak one drop, and no maintainence is required for the seals (as far as i know).
i'm not sure how old my M2 is, but i recall Al mentioning that refinements have been made to the M2's bezel over time to make it more reliably waterproof. i suspect the bezel of my M2 might have been manufactured prior to these improvements in design or manufacturing process. btw, my M2's serial number is A13966, so if anyone has an idea of how old it is, do let me know. anyway, i'm assuming the M2 bezel that is being sent to me will have all the latest design refinements, and it should be waterproof within all reasonable expectations, and that should solve the problem.
the cost of surefires are extremely high for flashlights, but i've chosen to rationalize it by factoring in the excellent customer service. you might have a 7 year old 6P, and surefire would still support you free of charge if it gives any problems. the extra cost you pay for a surefire goes a long long way and will probably last as long as surefire is still around
i just hope people don't abuse the system, since that would continually drive up the cost of surefire products in future. it would be kinda reminiscent of the british welfare system if that happened i think.