Error msg: XMLSchema:timeInstant is not declared

I was testing AccessXP export to an XML file functionality using the Northwind.mdb table Orders. The .xml and .xsd was created without any error. However, when I try to validate the Orders.xsd created by AccesXP using VBNet as well the multischema validator – msv (sun microsystem’s Kohsuke Kawaguchi) I get an error message on all elements that have the DateTime Access datatype. The error message was
“Type ‘http://www.w3.org/2001/XMLSchema:timeInstant’ is not declared.”…

Does anyone know what do I need to add/delete/change to get rid of this error?