I've had some problems as well...BIAB is doing some strange things on occasion - I save a file with a new name, and make changes - when I play the new one back, it seems to have put the new one on top of the old one, and I hear both versions at once....
Also - having issues with some chords... especially when I define a bass note other than the root... it plays the chord but ends it abruptly before the measure ends, and leaves only drums... very strange... but if I change the bass note to 'none' (plays the root) all is fine..... ???

And don't forget about the '08/Win 7 bug with Edit Audio - if you choose Adjust Output Level Quick, you will have to reload BIAB from scratch....