Ah what a day, half a day chasing an illussive schema around BizTalk

Problem
We have a BizTalk 2006 project that uses a mixture of schemas and .net serializble objects based on these schemas. Trying to be clever we decided to create port types and messages that were based on the .net type rather than the schema. Circumstances arose where we needed to mix the two up methods (using schemas and .net classes) within one orchestration\project. I kept getting the old message about there benig more than one schema for the inbound message, and I could not find out where this apparant other schema was.

Reason
If you use ports that consume messages that are based on a serializable .net type rather that a schema, biztalk automatically creates a schema for this .net type under the Biztalk.System application, try it, you will see a schema for your .net type appear.

This type is (obviously) based on a serialized version of the .net type.

Once inside the orchestration, it seems you can use this message as if it were of the type when passing out to helper classes.