It's done.

It turned out that in spite of the payment thingie always giving me the virtual finger (as in "your payment didn't come through"), the very first try actually had already succeeded. The next tries, though, didn't - partly due to my spending limit on the credit card which is ridiculously low on purpose, partly due to a security warning at the card issuing center. And I must say that even though I was a bit miffed at how paying didn't work as smoothly as I was used to, I'm happy to know that there is somebody watching over the card transactions and taking a closer look if something seems to be out of control.

So now it seems to be all cleared up, I'm booked for the conference, I booked a flight already as well, and I can go to Leeds. Hooray! Now I only need to figure out what to attend there out of the gazillions of different sessions, papers, and special evening events. I'll probably feel utterly lost at such a huge conference - by far the largest one I'll ever have been to.