this is the first time i have heard of such a thing happening.
i think you happily unscrewed your step up ring and/or polariser when you were fiddling around with it. this is not really the step up ring's fault, unless it is faulty.
sorry for being harsh, but if you had taken better care of your equipment (putting it near water without a logical reason, the horror!) this would not have happened. please remember not to go around rescuing stray coke bottles while changing lenses, if not you will tell people not to ever use lenses after you knock them into the water by accident.
just kidding about the above, actually. live and learn!