Trying to get my WCF service running under IIS 6.
I have created the .svc and aspnet_isapi.dll mapping according to: http://msdn.microsoft.com/
.svc
aspnet_isapi.dll
I had the same issue and solved it by allowing ISAPI extensions. Under Internet Information Service (IIS) Manager, open the node called Web Service Extension. Make sure that "All Unknown ISAPI Extensions" is set to Allowed.