Treatement of whitespace in enumerations

I have an restriction by enumeration as follows

<xsd:simpleType name="PropertySubType">
        <xsd:restriction base="xsd:string">
            <xsd:enumeration value="Cold Store"/>
            <xsd:enumeration value="Data Centre"/>
            <xsd:enumeration value="Design and Build"/>
            etc.....

If in my instance I have an element that uses the above data type and
say has value Data Centre I get an error

cvc-enumeration-valid: Value 'General' is not facet-valid with respect
to enumeration '[Cold Store, Data Centre, Design and Build,
Distribution Warehouse, etc.......]'. It must be a value from the
enumeration.

So it is not recongnising space seperated enumerations..

Schema is validated with Xerces 1.1

Thanks