fruitie, how often do you use amex in paypal?

i think if you only perform one transaction in a long time, then amex doesnt block paypal, or just something odd with their system.
for my case, i used to call cs to authorize in the beginning, then once i got lazy and tried using amex in paypal anyway.
to my surprise, it got through, but only for the first transaction, then it got blocked.
i tried again 2-3weeks later and it works again, but only worked for one transaction.