WCF might use the WS-* SOAP standard for communications but the WS-* specs leave vendors with a lot op maneuvering room when it comes to how to exactly implement things. As a result doing interoperable work between WCF and, for example, an IBM WebSphere server can be quite tricky to setup. Something I have experienced all to often
Fortunately Microsoft has now released the WCF Express Interop Bindings that should make live quite a bit easier. These binding are preconfigured for a number of common platforms like Apache, IBM WebSphere or Oracle WebLogic and should make things quite a bit easier. If only I could have used these several years ago, but you can now
Read more about the WCF Express Interop Bindings in the announcement here or here.
You can download them from CodePlex here.