I just found this on iLounge.com, in the Ask iLounge Q&A dated 5/2/08. (Ask iLounge is on the Articles tab of the top menu.) I read it quickly, but I think it relates to the problem discussed in this thread. The full answer has a lot more detail.

It's from the question that starts out :"I am a complete iPod novice and I am the wrong side of 50."


"The "Compilations" feature in iTunes and on the iPod is primarily intended to group these types of albums into a separate listing while also filtering out "one-hit-wonders"—artists that may only have done a single track on a movie soundtrack, for instance, and therefore don't deserve a place in your "Artists" listing."