I got a new fretless SX bass for X-mas. All in all I was suprised by the quality. Two things that weren't perfect were the truss rod, which would hardly budge, and a strange buzzing sound on the Bb adn Eb of the A and D strings (first "fret"). When I say strange buzzing sound I mean that it isn't quite the same as the normal buzzing you here when the string are to low, or there is a high spot on the board. So, since I wanted to replace the nut and finish the board anyway....I went ahead and did that. After sanding and flattening the board, installing a new nut, shimming the neck pocket, installing new strings, and setting the bass up it plays and sounds beautiful. But the buzzing under the Bb and Eb (first "fret") is not only still there it actually sounds worse. The only thing that I can figure is that its the truss rod vibrating under those two notes. I can't think of anything else, except maybe that the fingerboard is cracked. So, what to do?