I finally received my 40GB iPod about 4 weeks ago, and it had a duff hard drive. I could write songs to it fine, but as soon as I tried to read a song off it the unit would crash. Anyway, Apple agreed to take it back and refund me.
It's now been almost 4 weeks and it's still not been picked up; I phoned the Apple store and they have a "backlog on returns". I've never read any reports of people having trouble with these units before - is there something amiss with the new 10/20/40gb ones?