I have searched the forums several times for a similar problem, but haven't found any.

My 4th string("G" in standard tuning, or in my case F) sounds different from the other strings, it's some sort of un-even vibration, not really sure how to explain the sound.
It's not a rattle or buzz, it's just some sort of vibration.
It's barely noticable when playing clean, but you can hear it alot when distorted.
Not really sure where the vibration is coming from, but as I can hear it when fretting, could it be from the bridge saddle?

I had the same problem before, at the B-string, but it came when I had used that pair of strings for a while. When I finally changed strings to a higher gauge, it was on the G string instead.

Someone here should know what's up with the string, and how to fix this.
do you have a tune-o-matic bridge? the retaining wire for the saddles on those bridges can get stretched out and loose, and buzzes like mad and it's annoying as hell. i have thisproblem on my lp. i bought a new retaining wire for like 5 bucks, but i havn't put it on yet. hopefully that solves the problem.
No, it's a Licensed Floyd Rose(Jackson). I find it kind of strange that the "vibration" stopped at the B string and moved to the G string instead. Only thing I've tried to do about it is to tighten the nut clamp at the saddle, and also cleaning the string and removing dust, but that didn't help alot.