I've been using mp3tag for quite a while now, and I've had to put up with this annoyance since I started using iTunes.
When I save ID3 tags into an mp3 file and import it into iTunes it reads: "ARTIST - TITLE", with the ARTIST and TITLE names substituted to the actual artist and title tags.
But after I play the file in iTunes, the name reverts to the correct title tag (with just "TITLE" displayed).
If I empty my database in iTunes, and re-add the songs, the same thing happens.
The only solution I've found is to convert the ID3 tags in iTunes. Is there anyway to skip that step and completely solve the problem? I'm encoding my mp3 files with both ID3v2 and 3 if that helps.