Are your tracks frozen in the Mixer? The snowflake buttons would be blue if they are and therefore the tracks would not follow any new changes to the song.

After making sure they are not frozen, click the Generate button again.

Attached Files (Click to download or enlarge) (Only available when you are logged in)
freeze_track.png (25.97 KB, 51 downloads)
generate_modern_view.png (8.16 KB, 51 downloads)

Best,
Chantelle