I've upgrade one of my sites form 1.3.5-1.3.7 (via 1.3.6) and all seems ok apart from the Paypal express checkout.

I've set it all up with the api stuff and the button shows up in the cart and when you click on it, it seems to be working then you select to review the order, which sends you back to the site with the "checkout with paypal" select you then click the continue button to go to the order confirm page, but when you click to confirm it sends you back to the delivery info page.
When you continue through it again, it sends you back from the confirmation page to delivery page again.

I turned on the debug and this was the only thing that looks dodgy:

Response: array (
'TIMESTAMP' => '2007-01-01T14:41:05Z',
'CORRELATIONID' => '949c4542c5c30',
'ACK' => 'Failure',
'L_ERRORCODE0' => '10725',
'L_SHORTMESSAGE0' => 'Shipping Address Country Error',
'L_LONGMESSAGE0' => 'There was an error in the Shipping Address Country field',
'L_SEVERITYCODE0' => 'Error',
'VERSION' => '2.300000',
'BUILD' => '1.0006',
)

Further up the log is this: 'SHIPTOCOUNTRY' => 'UK',

A different log give this:
[messageToStack] => Array
(
[0] => Array
(
[class] => checkout_shipping
[text] => An error occurred when we tried to contact the payment processor. Please try again, select an alternate payment method, or contact the store owner for assistance. (10725)
[type] => error
)

)

)


Any help would be great.

Thanks