ok, i've been playing with this Pbass for a couple of years now on and off. i have a great mim jazz with emg's, so the pbass just sits in the closet. i decided to pull it out again....... the neck has a disgusting amount of bow in it. i tightened the truss rod, nothing. as tight as it would go. nothing....so, it seemed the truss rod nut was running out of thread before it pulled the neck to a reasonable tension. with the truss rod nut off, hitting the neck makes a noise like plucking a spring, so i assume the truss rod is still anchored just fine at the headstock end (adjustment at heel). so, i went to home depot to find some washers to put under the nut. of course the rod is some wierd size, so they didn't have what i needed. so, i continued to the local long & mcquade with just the neck. the guitar tech there took a look at it, tightened the nut as far as it would go, until there was some back-bow in it, and said string tension should straighten that out, and i may even need to back it off a bit. i was a bit worried about the fact that he just tightened it all the way all at once rather than in increments, but i figured maybe it's ok, if i let it settle long enough. i bought light strings (.045-.100) to reduce the tension, and put them on, left it over a weekend to settle, and the bow is just as bad as before. it seems to me his advice was way off, since i had already tried tightening the truss rod, but maybe he just wanted to eliminate the obvious: that i hadn't tightened the rod enough.... should i trust his judgement, assume he was just covering the basics and go back to him? or should i be finding someone else to look at this thing? i don't know what to do.