Is the last MIDI note in the sequence perhaps a hold and it is entered in or about the same place where the drums cutoff? The program may be calling the last note the End of Song and not the last barline.

Extend the song out a bar and add one MIDI note on any track at the last beat of that bar, then redo the drums and see what happens.

That last MIDI note can be edited off after mixdown...


--Mac