I've bypassed the shipping quote problem by setting a default shipping rate in the database and instead of redirecting to the "shipping_failure.php" page, it now sets it to the default rate on failure..
It would still be good to have the international postage calculation work if you know how, but not a big problem..
The Paypal button is still a big problem though.. What files do you need to look at for this. I have it setup with the PayPal express checkout option using a signature, and if you click on the "checkout with paypal" button it goes straight to the "pp_checkout_failure.php" page...