"How can we possibly make this payment process more annoying?"
And for future generations looking for what to use instead, I'm happy to recommend Indico. Free software makes for better conference experience.
@joeyh There's something wrong when a web shop makes it difficult to give them money.
Awful, but at least it functions, unless you can't type numbers under time pressure anxiety that includes being forced by update motion to read unrelated numbers, which [sarcasm] can't possibly account for the sudden rise in typos I'm sure they've seen... Ebay actually locked me out of my account for starting three consecutive orders and backing out of them without completing. (It was the only way I could find to check import duties.)
'at least it functions' .. I spoke too soon.
@joeyh And they reason they'll give if asked will be "security".
Someone walking up to your (unlocked) machine while you've left the purchase window open with your payment details filled in.