Thanks. Another issue. Like an idiot I booked using Aadvantage miles and secured a Ord-LHR; LCY-AMS ticket, thinking the transfer from LHR to LCY would be relatively easy. Having thought about it, I'd much prefer to do LHR-AMS. But I can't change or cancel my original booking without losing the good deal I got on miles -- we're talking about an extra couple hundred thousand miles to rebook.

So, here is the question -- if I do a separate LHR-AMS booking, with the intent to take the ORD-LHR leg of my mileage ticket and abandon the LCY-AMS leg, will BA flag that I am on two flights from London to AMS on the same day (one from LHR and one from LCY) and proceed to cancel one or both of them due to the double booking?