I've just tried to upgrade my brand-new account and PayPal has blocked me!

I came here from your other site, departmentals.com, because I have pictures I'm pretty certain you'll be interested in. Firstly, this site wouldn't let me use my own name, because, it said, it was "already registered". On the offchance that you already have another Robert Day, rather than this site picking up my registration for departmentals.com, I adopted a different - though transparently similar name ("Robert Day II") - and that passed the test.

Then I saw that to access additional features, including some of the photo lists I might well be interested in, I had to upgrade my membership. So I clicked to do that. I passed the "prove you're human" test (though I have to say, I didn't immediately identify the slider button as a slider), but no sooner did I complete that than the system came back to say that PayPal had been unable to load the next part of the validation page and so I was blocked.

Any ideas?