[oXygen-user] using catalogs

I've entered six new document types into "Document Type Association", 
and I'm getting much further.

The file I'm attempting to validate (shibboleth2.xml) contains these 
three statements:

	<import namespace="urn:oasis:names:tc:SAML:2.0:assertion" 
schemaLocation="saml-schema-assertion-2.0.xsd"/>
	<import namespace="urn:oasis:names:tc:SAML:2.0:protocol" 
schemaLocation="saml-schema-protocol-2.0.xsd"/>
	<import namespace="urn:oasis:names:tc:SAML:2.0:metadata" 
schemaLocation="saml-schema-metadata-2.0.xsd"/>

I've entered all three namespace values via "Document Type 
Association". However, I'm getting errors like this:

>SystemID: 
>/Users/stc/Sites/Projects/Shibboleth/Oxygen-2/Schema/shibboleth/shibboleth-2.0-native-sp-config.xsd
>Engine name: Xerces
>Severity: warning
>Description: schema_reference.4: Failed to read schema document 
>'saml-schema-assertion-2.0.xsd', because 1) could not find the 
>document; 2) the document could not be read; 3) the root element of 
>the document is not <xsd:schema>.
>Start location: 13:108
>URL: http://www.w3.org/TR/xmlschema-1/#schema_reference

for all three schemaLocation values....

Should I enter those values into new, separate "Document Type 
Association"s, or do something else?

Thanks!