Schema validation problem

In the latest XML Enc schema, the definition below generates an
ambiguous content type error on validation .  I'm not certain about the
best way to fix this, but believe we should fix it.  Any suggestions?

	<element name="AgreementMethod"
type="xenc:AgreementMethodType"/>
	<complexType name="AgreementMethodType" mixed="true">
	<sequence>
	<element name="KA-Nonce" type="base64Binary" minOccurs="0"/>
	<element ref="ds:DigestMethod" minOccurs="0"/>
	<element name="OriginatorKeyInfo" type="ds:KeyInfoType"
minOccurs="0"/>
	<element name="RecipientKeyInfo" type="ds:KeyInfoType"
minOccurs="0"/>
	<any namespace="##other" minOccurs="0" maxOccurs="unbounded"/>
	</sequence>
	<attribute name="Algorithm" type="anyURI" use="required"/>
	</complexType>

Blair