ModernBill issues with DA...

When i ModernBill trys to create an account on my server it fails but when one of the techs from ModernBill point it to my server it works what could be the problem? Here is the following message i get from ModernBill, Connection or 'createacct' function failed. I guess from what Andy at ModernBill told me is it is not responding to the cURL calls for some wierd reason, do you know what would cause that?

Never mind i found out the problem, anyone who has a custom login page make sure your ModernBill is pointing to the address that you have your custom page pointing to when loging in .