I recently bought a new iPod Classic 120GB, mainly to use on my Numark iDJ2 but also for general use.
I have it set so that all my iTunes songs are automatically pulled over to it and when I look at its contents on iTunes all my songs are there. However, if I unplug it and then search through it manually, some artists don't appear. (I haven't yet found a pattern.)
The only reason I mention my iDJ2 is that I have Numark's 'Librarian' software installed on my iPod so that the iDJ2 can categorize and play all of my songs. I don't see how it should be responsible for this problem though.
Any help much appreciated and let me know if you need any more info.