I don't see it either. Furthermore, people who I know used to have "Patronus" banners (indicating they've made a donation to the forum) have lost them (of course, we all lost our banners, but they also lost the "Patronus" title along with them.) It seems like the forum no longer wants to take our money.
Donors. 'Donate' is a back-formation, like 'enthuse', and came in for hefty criticism at the time it was coined. I think most people have accepted it now, though I'm not sure if 'enthuse' can claim the same.
Incidentally, I tried logging in with different browsers to see if it made a difference with respect to the button (it didn't), but I had to try to log in with Opera three times before it accepted the password. I know you're thinking I can't type properly, and you're generally right, but it was an assigned unmemorable numerical password, so I C&P'd it. In other words, I know that whatever was on my clipboard was rejected twice and allowed in the third time. If anyone can offer anything approaching an explanation, I'd be grateful.