Just booked some I class deals using an IB codeshare flight. The 'Manage my Booking' function allowed me to choose seats and I was a little surpsied to see all J class seats still available on the IB flight. Pre-selected seats and the choice was accepted and the seats shown as allocated on the home page of my booking. Went back to the booking later to find no seats assigned on the IB flight. Repeated this process several times with the same result.

Then thought to look at checkmytrip.com and found that several seats including one of those which I had chosen were already taken. Curious that the BA system shows an erroneous choice of seats.

Is this just a BA / IB problem or a more general issue where BA has accees to availability on other airlines ?