I have a pair of Fender's Mexican Jazz 4 standard and American Deluxe V. Both basses never seem to sound perfectly in tune to me. I tune ADGCF with 45 - 105 guage (130 on B) I like a straight neck and a bit of fret buzz for attack. Now, open string, twelfth fret harmonic, 19th fret harmonic sound perfect and are pretty much bang on - a few minor deviations due to the mass of the string accepted. Twelfth fret held down is in tune. However both basses sound a little bit out when I'm playing and it's driving me up the wall. I can't have picked up two lemons and the basses sounded fine when in the shop, etc... my problems have arisen from dropping the tunning. Aaaarrgghhh!!!