[support] Change in paypal ecommerce behaviour?

Hi folks, I've been running paypal payments via ecommerce for a few weeks, but all of a sudden, the final paypal checkout (on paypal itself) adds 20% to the total cost for delivery! I can't see where this is coming from. Also the usual product code information and description is gone and replaced with a transaction id. Has anyone else noticed a change in paypal behaviour with ecommerce 5.3 in the last days or weeks? Thanks Chris