Express Checkout removes UK VAT but WPP doesn't?

[legraphics]

I have set up a new site with ZC 1.5.1 and integrated WPP and express checkout.

When I do a test transaction the checkout correctly shows the net price plus 20% UK VAT giving a total price.

If I check out using website payments pro then I am correctly charged the full price including 20% VAT.

However - if I login using the same account details, purchase the same item but checkout using express then paypal express seems to remove the vat element and only charge the net amount - when I go back to my account and look at the order information page the vat has been removed!

Any ideas?

[legraphics]

Just wondering if anyone has any ideas about this - it's very frustrating!