Hi there, I'm running Shimano 105 10 speed with a triple chain ring on the front and have been having some wee issues... I bought a new gear cable for the front derailleur and needed to tighten it, but after doing so (and I don't know if the two events are related, this is just when I noticed the problem) the chain seems to be slipping on the rear cassette, or changing gears spontaneously (I'm not sure which I haven't actually watched whats happening). Basically, while pedaling the gear seems to change and the chain seems to move (I am guessing the gear is changing spontaneously) Does anyone have any idea what could be causing this, or have had any similar problems and could provide guidance? Cheers.