Paypal error, but not in Opera (partly)

[panhead]

I have the same error as many others, Paypal payments are not processed. I looked at all solutions mentioned here, checked and double checked my API settings, but no luck.

I work in the production environment, use the latest Paypal module.

 

What I found out is the processeing payment with Firefox en Chrome give a blank page, just nothing happens. However, when I use Opera I get the following message:

 

Fout

https://www.paypal.com/nl/cgi-bin/merchantpaymentweb?cmd=_flow&SESSION=Fe_ywLfqtHTlCdndJa9gSru9dAGo3AOKnJFY7Wft7JiJedixQN7kx5rwaBa&dispatch=50a222a57771920b6a3d7b606239e4d529b525e0b7e69bf0224adecfb0124e9b61f737ba21b08198d4932d04262264a8f2ad7cb498e6e144

 

De website staat niet toe dat zijn materiaal in een kader (frame) wordt getoond. Dit moet in een apart venster worden getoond. (the website does not want its content shown in a frame).

 

Document in een nieuw venster laden If I open in a new tab everything works fine and Paypal works.

 

This proves that the API settings are right. Now how can I make it work in Firefox and Chrome?