I've got a 2012 American Standard J bass that I bought brand new from GC about a couple weeks ago. I immediately took the stock rounds off and put flats on. I wanted La Bella's, but GC didn't have them in stock, so I got the sales guy to throw in a set of Rotosound 77's with the deal and I put those on as soon as I got it home. They sounded fine, but I wanted the La Bellas, so I ordered a set. I got them yesterday and installed them. When I went to play my bass this morning, the open E and open A string have this terrible rattle when I play them. The D and G string don't. I looked at the nut, and the strings seem to fit there just fine. What gives? Thanks!