xmlsectool failure

[Liam Hoekenga]

I'm trying to validate some metadata using xmlsectool.

./xmlsectool.sh --validateSchema \
--schemaDirectory=/usr/share/xml \
--inFile=/home/liamr/InCommon-metadata.xml

The error I'm getting is..

ERROR XmlSecTool - Invalid XML schema files, unable to validate XML
org.xml.sax.SAXParseException: 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>.

I'm using Sun java 1.6.0_27 on CentOS.
I've tried multiple versions of xmlsectool (1.1.4 and 1.1.5).
I've tried pointing it both at the system collection of schema docs,  
and a copy I made specifically for xmlsectool that only contains that  
opensaml, shibboleth and xmltooling definitions.

Using strace, I can see that it does locate  
saml-schema-assertion-2.0.xsd, and that it's readable, so I'm guessing  
the problem is option 3?

I've tried it on locally generated metadata and the InCommon metadata  
to the same result.

What am I missing?

Liam