Well... after some time trying anything and everything I could think of, I'm pretty sure I've fixed the problem. I removed and then reinstalled the drivers for my Focusrite 8i6. The BIAB plugin now plays normal within Cakewalk. Haven't had time to check it out in Reaper but will give it a try tomorrow.

That being said, the song is still ending 3 bars earlier than it should, but that could be because of something I did when creating the song in BIAB. I'm going to do another one from scratch and then see how that goes.

Bobby