Pay per View payments not going through

Hello
I have an issue with the Pay per View plugin, payments are not coming through. when the PPV button is clicked, i am directed to paypal, i put the payment info, then i am redirected to my site with the error "There was a problem connecting to PayPal to setup your purchase. Please try again.".
- I checked with PAypal, my account is ok so is API
- My developer tested it on his server and it worked out fine
- I am using Hostgator
Can you please give me some guidance as this is preventing me from launching the site?

thank you