MarketPress Pro. When you have VAT inclusive prices, why doesn't it send the VAT value to PayPa

When you set up a product with a VAT inclusive price, it correctly shows the VAT (taxes) on the checkout page before you go to PayPal. When you go to PayPal purchase screen it doesn't show the VAT - just the total price including the VAT.

If you have VAT exclusive pricing. It shows the VAT on the checkout screen and then shows the VAT in PayPal purchase screen.

Why is this?