Working on a tele with a fretless neck (please hold your complaints). The issue is a spot where the same note spans across half-steps. What it should play is: C-C#-D-D# Instead what is plays ;s: C-C#-D#-D# Is this cause by a spot on the fretboard that's too low, too high? Or something else entirely? Stop me before I sand again (unless I, in fact, do need to sand again).