I'm getting strange notes occurring when I fret the strings on my acoustic bass above the 7th fret... They're even being picked up by the bridge transducer... I find that if I use a spare finger to lightly mute the portion of the string above the fretting finger the note dies... so it appears the string above my fretting finger is vibrating. I'm not sure if the string above my finger is actually making contact with the fret above or not, but I suspect it is as there's no perceptible give when lightly pressed. I'm consciously trying to fret as close to the fret as possible without being on top of it and choking the note. I'm not getting any fret buzz at all when playing, so the relief and bridge are correct. I've checked the string heights and they're the same as listed on the QA card that came with the bass. The bridge is not adjustable at all (without going to a luthier) so the only adjustments I can make are changing the strings and/or slackening off the truss rod slightly. Tonight, I'm going to try an eight turn anti-clockwise to see if it helps or not.