I have the same problem, MacBook Pro, iTunes 10.2.1, MusicSphere 1.0.0. iTunes has 2990 songs total of which 49 have DRM. MusicSphere is only finding 1346.
Approximately 2930 songs are mp3 so I don't believe it's a file format problem either. Any ideas on what the problem may be? Synced a few times and it completed each time, no new songs though. I'm tempted to review the xml file which likely has the list of 1346 to determine what it didn't take but first wanted to see if anyone else had other ideas.
Thanks