I've just hade a sperzel locking tuner bite the ends off of four plain steel strings while I was tuning them up to pitch. It's almost like it knows when I'm getting up to pitch because it always breaks them just before they get in tune--and I even tried a heavier gauge string to see if it would work better and because I ran out of smaller strings. Same results. I've had the guitar for going on seven years, and now seemingly out of the blue the tuner-in-question is "eating" strings like candy. Is there anything I can do short of replacing the problem part? Is this a common thing?