Here is a better example of my problem. Consider the XML below.

<ns1:project xmlns:ns1="http://www.namespaces.com/ns1">
          <ns1:elementOne xmlns:ns2="http://www.namespaces.com/ns2">
                     <ns2:elementTwo>Data</ns2:elementTwo>
          </ns1:elementOne>
</ns1:project>

I know this is a strange way to declare the second namespace 
(under an ns1 element), but according to the XML spec. any child element to 
ns1:elementOne will be able to use the ns2 namespace.

Also note that in my schema files I don't use any imports or external 
references.

So the problem is as follows. If you change the URI for ns1 to something 
unknown
by my schemaCache ("http://www.namespaces.com/ns1/junk" for instance) I get 
a validation error from MSXML 6.0 saying the namespace is unknown.

If I do the same thing to the URI for ns2, I get no error. However, if the 
ns2 namespace is known, it WILL validate all the elements under ns2.

In MSXML 4.0 this was not an issue. I encountered it when moving to 6.0.

Any suggestions on how to fix this, or where else to go for help?