Problem with PayPal Buy Now button

[donjohnson24]

On my web page http://www.donjohnson24.co.uk/woozlebird.html I have three PayPal Buy Now buttons to make 'one off' purchases as simple as possible for users who usually don't have PayPal accounts.
The first two are for buying plans for delivery in or outside the UK
Originally, I added the shipping costs of £4 and £10 in the Shipping 'Base Shipping' boxes on the parameters for the buttons,
But the shipping costs DID NOT appear on the first transaction, so I removed the Base Shipping entries and added the appropriate sums to the basic prices and re-uploaded the page.

To cover the missed shipping cost for the first (USA) transaction, I added a £10 Buy it Now button, and asked the buyer to use that to send me the balance that had not been charged. I tested this and saw the correct £10 amount appear, but did not complete the transaction. However, when the buyer used the button, and completed the transaction, an additional £1.50 charge appeared for shipping, which he rightly complained about.

I have searched all the parameters for the buttons, but cannot find where this £1.50 shipping charge comes from.
Can anyone please give me a clue as to where it originates so that I can delete it.

Thanks,

[BaconFries]

Wouldn't it be easier to just have one button along with a drop-down (combobox) with the three shipping costs that the buyer selects and will be passed onclick of the button.

[donjohnson24]

Thanks, but I only need two buttons - the third is just temporary to get the missed shipping cost.
But I want to be sure that the unwanted £1.50 basic shipping does not appear on the the other two buttons, so need to find where it comes from.

[BaconFries]

The extra £1.50 could simply be a charge applied by PayPal to the customer if payment was made by credit / debit card ie a transaction fee. Just my two cents I still think one button two shipping in a combobox is neater...but hey who am I to say...
Note I have viewed the page source and don't see any reference to £1.50 so as mentioned it may be a transaction fee.

[donjohnson24]

Just to confirm, this is part of the PayPal detail for the transaction with the extra £1.50, which indicates 'Postage'

Perhaps I'll have to ask PayPal . . . . Later, No! They couldn't help! Weird!

Hopefully, when I delete this no longer needed button, the others will be OK