Came across this problem when my b/f gave me an Ipod last week. The artist showing correctly on itunes was not showing at all on the ipod when you went into the “Artist” menu, and you could only find the artist when looking through the “Album” menu. Frustrating – and concerning that you might miss your music when flipping through artist when deciding what to listen to! In particular this was happening to my Gwen Stefani album (not sure why I am telling you that particular detail!).
I looked this up on the net and got some advice to update (in bulk) the artist name to itunes. For me this didn’t work as the artist was already correct in itunes. In the end the ever clever b/f went through menus on the ipod and realised that some albums were categorised “Compilation” for some reason (it may be because they co-wrote the album?).
ANYWAY – I highlighted the artists concerned in itunes and went to “Get info” – I then went to bottom right of info box and checked “NO” under compilation and then synced my ipod. Problem solved!
Let me know if this has happened for you and if this helps at all! 
S
