Updated: PayPal UK is currently down. Although the front page seems to be working, anyone logging in is met with a server error message.
Four Register readers tipped us off to the problem, which we suppose is at least a sign of its popularity.
The page is currently showing:
Internal Server Error
The server encountered an internal error or misconfiguration and was unable to complete your request.
Please contact the server administrator, email@example.com and inform them of the time the error occurred, and anything you might have done that may have caused the error.
More information about this error may be available in the server error log.
Bad news for etailers and even worse news for eBay, which increasingly encourages all its buyers to offer PayPal as a preferred payment method.
We've called the company's PR agency for comment and will report back when we hear more.
Update: PayPal called at 11.50 BST to say everything is now working. They're investigating the outage and are not sure if it was caused by the upgrade. All payments have been recovered and will go through shortly. The site was down for about an hour.®