I recently had some terrible open a string buzz on a fender jazz. It wasn't even musical just a bunch of racket. I tried everything even a string retainer to no avail. Today I said the hell with it and put a tiny piece of paper in the nut slot and strung it back up. NO MORE BUZZ!! Is it that my nut slot is to shallow ? Or maybe to wide from a heavier gauge string? How can I fill this instead of getting a costly new nut made ?