Thank you Rharv, Bob and Noel,

I've updated my BIAB to build 845;
Double and triple-checked tempo in my DAW;
Saved as WAVs that are native BIAB i.e. 16/44

Tested it with three fairly complex songs and it's all been fine. Thanks to you guys I've now discovered more about some of the time options in my DAW and I suspect that's where the issue lies. I'll keep an eye (and ear) out for it over the next little while.

Thanks again!

Killer