I booked 5 flights yesterday on ba.com. The first 2 went through payment so slowly that it reminded me of when BA had the XSS hack going on and I was worried my card details were being intercepted. The 3rd one went through quickly and then the 4th and 5th were again painfully slow.

There's clearly something up and it must be harming their conversion. But if the planes remain full (and I haven't been on a BA flight recently that wasn't full) then maybe they're not so worried.