Can't get the correct parameters from PayPal's new screen

I'm developing an application in rails, my problem is that now with the new design of PayPal's screen, when it redirects the client to my web page to notify him if the transaction has been done correctly, I only get in [:params] the controller's and the action's name, when I should receive this two parameters: [:payment_status] and [:payer_status].

I'll try to exp开发者_如何学Clain it better, sometimes, when the user finishes the checkout on my web page and clicks on the "buy" button, my page redirects him to a PayPal screen that has the description of the products bought in the top of the page, and sometimes to another screen that has the description in the right side of the screen.

After he pays on PayPal, he has the option to return to my page, where he would be notified with a message like "The transaction has been done". The problem is that always that the user is redirected to the second PayPal screen, after he pays and returns to my page, a message like this appears "The transaction could not be finished correctly", because like I said before I don't get the correct parameters. But always that the user is redirected from the first screen, I get the correct parameters and I can show the "transaction completed" message correctly.