I use fb1.5b20 for some time and I noticed that when playing SACD as a whole, everything is ok.
When doubleclick on 1. song, 1. song is played.
When doubleclick on 2. song, 1.song is played again.
When doubleclick on 3. song, 2.song is played again.
And so on...
Last song is never played directly, only if I play the whole SACD .
I tried SACD plugin several versions back and with all - the same behaviour. DVDA plugin from the same author behaves correctly. It worked also with stable version 1.4.8 if I remember well. I am not sure if I can downgrade FB.