WHMCS integration payment issue. 'Hanging'

Hi,

I'm trying to set up a network for creating sites (cascoweb.nl) and a payment/administration site (cascopay.com/administration) to handle finances.

Now WHMCS on cascopay.com is up and running (not in production yet) and paypal connection is made. It seems to work o.k.

Next i installed WHMCS integration on cascoweb.nl/hosting to see if i can make the connection from there. I created some products, and the ordering is technically working.

BUT, when i actually want to order, and make a payment via PayPal (or iDeal) there is no action going on. The order button keeps telling that i have to wait. No errors, just waiting and waiting.

So something must be incorrect in my settings or specifications, but i really coud use some help on this one.

Would you someone be so kind to test my site, and help me out.

I would love to hear from you.

Kind regards, Winoman