I just got a replacement clip for my LX2 in the mail today (talk about overkill packaging, lol).
It's the first time mine has broken, but then I've only had the LX2 for less than a year. It broke while sitting inside the pocket. I had put it in (without clipping) while in a hurry and when I went to take it out to clip on the pocket I realised it had snapped off.
I inspected the newly arrived clip before putting it on, and noticed that the clip is made in such a way that the part near the clip mounting point (where breaks usually happen) is constantly under stress from the other end of the clip pushing against the tailcap. Could this be a factor in why so many clips are breaking, besides the fact that clips are actually designed to break?
P.S. There are a few other threads about the LX2's breaky clip, there's some useful info in those as well, IIRC.