Did you write your own WS-Addressing implementation?  Do you want to know if your stack will interop easily with Microsoft's? 

Doug Purdy points out a fantastic resource... mssoapinterop.org.  Use this to find out where potential interop problems are between your stack and Microsoft's.  You can review the results of previous interop runs against multiple stacks as well as use a host of tests from the Interop Plug-Fest where the WS-* specs were exercised.