What I did different than before (though I don’t know if it was the solution !) was
I added 1 item to my cart first, placed order, checked PayEx amount. Which was o.k.
Then went back to add a second item in cart and placed order; and PayEx discounted amount
for both items was right so went on to Paypall.
I’ve allready made a suport ticket yesterday with two screenshots of
the ‘Your Order’ page with right (discounted) amount and after [place order]
the one with the bloody PayEx bill that increaes the amount.
When I go to paypall next to check, it’s the wrong amount (and refused too).
