Paypal button on unpaid order does not rediderect correcly

[vitovito]

I really appreciate anybody can give some tips on how to solve this issue.
Clients who access their account in order to pay an order, when they click on the paypal button the browser return with the following message:
Access Denied

You don't have permission to access "http://www.paypal.it/cgi-bin/webscr" on this server.

Reference #18.671d434d.1346699247.14af7d8

Instead Regural checkout when placing the order works as usual with not issue.
Anyone can give any idea . Thanks

[vitovito]

I solved the problem, i was directing to paypal.it instead paypal assistance told me i should point it to paypal.com , that solved the issue