Xcbl 35 schema validation problem data validation

I created a record structure and schema in wM 4.0 using a .dtd file, and a .xsd file. I am able to do schema validation (tag structure) using pub.schema.validate, but I am not able to do data validation (date format, empty values for required fields).

Strangly enough, I am able to do data validation on the xcbl 3.5 order status result document using the same method. I have tried to find uncommon elements in the document to find the root cause, but was unsuccessful.

Has anyone come across this same problem, or may know what I can change within the xcbl document in order to get both webMethods to accept the .xsd and create teh scheam, then also having that schema do data validation.