I got another one. Eastman acoustic, 12-54 strings. Customer wants lower action, fingerpicker. I got it to 2/32 at the 12th, had to do a fret level/dress. D string still buzzes around the 5-9th frets. Relief is correct, saddle looks good, radius correct. Tried new string. Why does the D string buzz noticably, when the others are ok?