Hello, all. I recently purchased a new bass from my local violin shop (www.stradviolin.com), and although the bass sounds amazing (a huge upgrade from the one I was renting previously), I've run into a problem. One of the tuning keys is loose and is causing a rattling sound when I play notes on my A and E string. The part that is loose seems to just be fitted in there, and there isn't any screw holes or anything. Any suggestions on how I can fix this problem?