I just wanted to suggest that, if you have any WD-40 lying around, lightly squirt some on to the button face of the controller. Make sure that it get's into the crevices of each button that "sticks." Then dry the controller off, or better yet leave the controller out so it dries and any of the scent from the WD-40 dissipates (it's probably not a good idea to inhale the fumes too much but if your desperate to play feel free too, just don't hold me responsible). There is a good chance that this will solve the problem.