i built the neck on my les paul out of soft curly maple. no problems whatsoever. after the frets were leveled, i diddnt even have to adjust the truss rod after it was strung up. dead straight. but i live in new mexico, which is like arizona. not much humidity to change the wood. but it rained a ton yesterday and left it on a table on the porch, and it diddnt change a bit.
curly maple neck:
http://i206.photobucket.com/albums/bb262/k...ulguitar007.jpg