WCF team released a patch to help you if you’re using WCF on Windows Azure. Essentially, if you use "Add Service Reference..." feature in Visual Studio or svutil to generate WSDL for a service that’s hosted on Windows Azure either locally or in cloud, the WSDL would contain incorrect URIs. The problem has to do with the fact that in a load balanced scenario like Windows Azure, there’re ports that’re used internally (behind the load balancer) and ports that’re used externally (i.e. internet facing). The internal ports were showing up in the URIs.
More info: KB971842