Business Process setup - Orphaned Messages

I am still trying to track down orphaned messages and have noticed that when we have Business Rules that send to a Business Process that some times there is an orphaned message that is generated as result of that send. 

• So my question is, is there an issue with the way that we have setup our Business Processes as they are setup with a request class of Ens.Request, and a response class of Ens.Response when the message is truly an HL7 message?

• Shouldn't the request class and response class be EnsLib.HL7.Message?

• Why would an orphaned message be created from the send from a Business Rule to a Business Process?