I have an Epiphone Les Paul Standard 5-string. I can intonate the higher 4 strings all day either way, but the B has reached the limit. It harmonics exactly on the "B" note, but when carefully 12th-fretted, it reads sharp. It is an audible difference, as well. The tune-o-matic saddle is as far back (towards the tailpiece) as it will go. I have loosened the truss rod about 3/4 turn (1/4 - 1/2 turn a day, I know) and after letting it settle for about a week and a half, re-tightened about 1/2 turn. No effect on the intonation either way. Any suggestions, or should I just tune a smidge flat to compensate? Thanks.