Problem with .NET - Invalid particle derivation by restriction

In the attached set of files .NET objects with "Invalid particle derivation by restriction" at line 22 in ComplexConcept.xsd

No other validator I have tried gives the same (or any) error and I can't for the life of me figure out what might be the problem (nor can a whole host of other very smart XML knowledgeable folks around the world that have looked at this)

Could someone please confirm what is wrong or what is right please

Many thanks

Hugh Wallis

************************************************************************

If you have received this e-mail in error, please delete it and notify the sender as soon as possible. The contents of this e-mail may be confidential and the unauthorized use, copying, or dissemination of it and any attachments to it, is prohibited. 

Internet communications are not secure and Hyperion does not, therefore, accept legal responsibility for the contents of this message nor for any damage caused by viruses.  The views expressed here do not necessarily represent those of Hyperion.

For more information about Hyperion, please visit our Web site at www.hyperion.com