Is any body getting bad behaviour on PayPal payments?

I have odoo 8 (OCA) and installed payment_paypal. When I tested on sandbox.paypal, everything runs fine, control returns to my website and displays SO payment confirmation. Also, SO is confirmed and registered the PayPal transaction.

When i change mode to production, PayPal shows a totally different interface, accepts payment and can't return to payment confirmation.  I have been doing tests looking into code and realize DPN send an incomplete set of data (compared to the sandbox test) and confirmation ends on INVALID state so can't reach the payment confirmation code.

I don't see to much people complaining about this issue, so i hesitate it could be my fault.

Do any of you know something about this?

... regards ...