I am a new user of iTunes. I am unable to import MPEG-4 audio files from an audio CD into my iTunes library. This audio CD was created by a friend on his MAC.
Interestingly, I am able to play the same MPEG-4 files through my Windows Media Player. I have the most recent and updated versions of Quicktime (7.4.5) and the most updated iTunes player for Windows (188.8.131.52). Coincidentally, the same audio CD has some MP3 files which I am able to import into iTunes with no problem.