Yes. I click the donate button, log into Paypal, and it gives me an error message saying that I can't use my credit card for this donation, and would I like to link a bank account directly to my Paypal instead?
The credit card works on Paypal for other things. It just doesn't work for donating to Bay12. And as I have no intention of giving Paypal (or anyone else, for that matter) direct access to my bank account, I'm unable to donate to Bay12 at all, without resorting to ancient, barbaric practices like writing symbols indicating value manually on crushed plant fiber with a chemical pigment, and then hiring a meat-puppet that rides around in a metal box which burns dead sea-life to physically deliver the crushed plant fiber to Toady, who then has to physically take the crushed plant fiber to a big building with more meat puppets in order to re-convert its imaginary value into something he can use to barter for produce, or things that come out of chickens, or some sort of dead animal which he can use in a chemical reaction to produce enough energy to make his brain work in such a manner which is conducive to his improving hauling in Dwarf Fortress.
Edit: I just tried it again, and it worked. I'm assuming it failed the first time for security reasons, as I was attempting to donate while I was out of the country and there's some sort of check to prevent that, or something.