I have the same problem with paypal mexico. I need it because i want to recieve in usd and pesos.
I am still busy to editing my site with with a lot of details and testing.
If i make a upgrade in the back office it says upgrade succesfully, current version (1.2.5), but nothing changed.
the installed version is 1.2.5 and i says 1.2.6 is available.
If i go to the website addons there it says current version 1.2.6 but is i download the addon the file name says 1.2.5
I don't remember for sure (or there was no update available) but i believe i upgraded to 1.2.6 a week ago and it worked fine (i had a problem that when i paid with bankwire that a message popup that the credit card transaction failed) so i uninstalled both payment modules and reinstalled it.
Did they put back the old version or did they forgot to put the right version under the download link.
Prestashop 1.5.5.0
After that i did a lot of changes and started with a new install. And got this issue with paypal.