I have True Bass 88s on my short scale Musicmaster. I came out of the studio where my fretted [low] G had an overtone according to the engineer. Luckily, he had a Precision in the studio and I switched for that track. I am also told that my fretted B is out of tune. The bass is intonated correctly, and in tune. I had the old Fender bridge replaced with a new Gotoh. It's been worked over and checked. Has anyone had any issues such as this with black nylon wrapped strings?