Woocommerce validation error

Hi
Since upgrading to the latest version of woocommerce I am getting the following error message:-
‘Validation error: PayPal currencies do not match (code GBP). Order status changed from pending to on-hold.’
The payment is made via paypal and processes ok – eg I receive the correct amount into my paypal account, however the order is put on hold and I get the message above.
for info, I only do business in GBP and do not use any other currencies.

I never had this issue before the upgrade to the latest version of woo commerce.
Many thanks