I changed the bottom-bracket in my mountain bike two years ago, the problem was that the bolt on the crank on the non-drive side was continuously getting loose, to the point that I had to stop and tighten it again every mile.
With a new BB the bike was all right, and it worked fine for almost two years (I wasn't using it that regularly though). Until last week, when it started having the same problem again.
The BB is a part of the bike that usually lasts forever, so I'm not really convinced about changing it again, because the current one lasted so short, I think there could be some other problem in the bike, that causes the BB to wear faster. But I haven't got a clue about what that could be.
Does anyone have experience or thoughts about it?