Attributes on XSD Schema Bound Form

I have a form that is bound to a schema that has a definition like this:

<xsd:complexType name="File">        <xsd:simpleContent>            <xsd:extension base="xsd:base64Binary">                <xsd:attribute name="fileName" type="xsd:string" use="optional"/>                <xsd:attribute name="mimeType" type="xsd:string" use="optional"/>            </xsd:extension>        </xsd:simpleContent>    </xsd:complexType>

The problem is that when the data is exported using Acrobat XI's Export Data (as XML) option, the attributes (which are not bound), are included in the output, i.e.

<FileValue fileName="" mimeType=""/>

Which causes issue when validating the schema, using XMLSpy. The output I expect (and need is this):

<FileValue />

Is there a way to accomplish this?