I've just recieved a text from BA advising of a schedule change on the LHR-MAD-LHR route. It seems the A330/A340 is now doing the 1830 BA522 service instead of the 1910 BA516 service. This would explain why IB was displaying differing info to Ba.com & Ba have just caught up.
I was able to call and rebook and surprisingly i recieved the BA text before the myflights notification.