Why does two albums get created instead of one!

I am having an issue where sometimes 2 albums will be created instead of one. There maybe 10 songs in one album and it puts one of the songs in another album.

For Example: Bee Gees – Greatest. Song #1 is Jive Talkin, but it puts that in a different album to the other 10 songs.

Justin Bieber purpose deluxe edition vs regular edition. The song where are U now keeps getting put in a separate album to the other 19 songs.

I have tried using MusicBrainz Picard to fix this problem, but had no luck. Any ideas would be helpful.

[img][Image: 30ml98y.jpg][/img]