What must be in place to validate a XMLTYPE against a schema?
My test case ran fine on multiple other databases and multiple sources (including oracle support) asked if the ANONYMOUS user had been dropped.  Although it had not, there were some XML DB Repository changes that were made without a full understanding.  To try short cut the problem I re-installed XDB using note 1292089.1.  This allowed my test case to work correctly and after dropping the created types and tables and re-registering our XML schema, everything worked correctly.