1. The popup to donate shows up on a page where the URL is not https. This looks wrong, but closer inspection shows that it is an iframe that is in fact properly secured. But had I not known how to find that out (right-click, show page info), I would not enter my credit card info on a non-https site.
2. My card was declined, the first time in my life that that has ever happened. I triple-checked the information I entered and it is valid. Could be my fault, but given I've never had a problem before, perhaps an issue with the site?
Based on those two things, this project might be missing out on some amount of donations (at least mine, since I don't have another card to try). Hopefully that's fixable.