I'm using the internal soundcard with ASIO drivers (much better sound quality than MME). The songs all play fine directly through BIAB, only mess about when they've been rendered. It isn't always real drums, real guitar can be a bit dodgy too - only happens if I've put a rit in the song (Don't cry for me Argentina), or the drums come in half way through the song (as on Nobody does it better)following a tempo change. I've got several songs which are medley's and playing them 'live' through BIAB works fine. I downloaded the drums set 1 - 121 update patch just now, and the latest build 318 (again) - hasn't helped at all. I'm pretty certain it's a glitch with the software rather than my PC.