I cannot get past the checkout page on Ebay, though when I rang ebay, assuming they were the problem, she found it worked for her. She asked what browser I was on, and it turned out the checkout page works perfectly on chrome but on firefox, the 'continue to payment' box remains greyed out and useless. I've closed and reopened ebay, restarted my macbook pro, then turned it right off, and on again. No joy, hoping someone here can explain or help solve this issue?