courtesy of sportandplay:

OK, is it problem with Firefox, and it is OK to log in with IE and pay, or is it a problem with eBay that only Firefox detected?

I have read that you need to click on pay now under purchase history in my eBay

I just paid on my ipad no probem and chrome seems to be ok, guess we will find out but I just had a large sale and the buyer had to get her friend to purchase on her account, this is before I knew about the firefox problem but it could be more widespread, not sure.

I tried from the item when I bought it, and also couple of times from my purchase history.  I have contacted the sellers and one responded that he is not in hurry.  I might just leave it till the morning.

Can you just go straight to Paypal and pay from there without going through the ebay gateway?

I wonder if it's been fixed yet?? I hope so

Yes, it is fixed now. 

I could just send the money to the seller directly from PP, but I do not think that seller with several thousands of items listed would be over the moon if they started getting few dollars payment that they had to be matching to sales.

that's good news, thanks Nova