Hi, I'm little bit fighting with the PayPal button. I have the unencrypted version which works great, the problem is that the customer can change the amount etc. I found out that is possible to encrypt the data. I used these two examples: http://bit.ly/c5GpEQ and http://bit.ly/9I7pvJ . The problem is that I'm getting 'We were unable to decrypt the certificate id.'. Maybe it looks like I don't have right PayPal public certificate? I downloaded it from the backend, the only one I found. There wasn't any reference where to download it in non of the turorials. I'm trying this on sandbox right now. Please can anyone advice?