Virtual Item, Paid via paypal, charges postage...

I have a virtual item available for download when payment is made, no shipping is set (e.g. no weight or anything is set).

I noticed that if I pay for my virtual item via check, it charges me the fee for the item ONLY. Once confirmed it is available for download in the orders section. This all works fine.

I have however noticed that if I pay for my virtual product via paypal, when I get to the payment screen in paypal, it is trying to charge me postage..?

I only have one postage fee set up which is for another item I am selling, which does need to be posted.

My settings for the virtual product regarding postage are all 0 as obviously it doesn't need to be posted.

Any ideas?

Yep I have bought several of my items as I am just testing at the moment, within the same session.

Ok just going back to it now, I see the postage added on the checkout (even though the option isnt there).

So surely though this is some sort of error? Because if no postage is set within the product (weight etc), then NO postage should be charged.

How do you go about fixing that with sessions?