I fixed my old right one a while back by ripping the coating (whatever you call the grip layer) off the stick and realigning it. Supposedly if a bit of old skin or dirt or whatever gets in there it can be fickle enough that that may throw it off a bit. Worked for me anyway, so I'm happy. Prior to that, the bloody thing would drag a bit up or down occasionally, started right after the warranty ended so I coped for a while until I heard about this method and it worked fine. Go figure.