Problem defining Relationship XML

["Murray, Bryan P." <bryan.murray@hp.com>]

I am having a problem defining a schema for Relationship that validates.
The pseudo-schema for Relationship (from MUWS part2) is the following:

<muws-p2-xs:Relationship>
  <muws-p2-xs:Name>xs:string</muws-p2-xs:Name> ?
  <muws-p2-xs:Type>muws-xs:RelationshipType</muws-p2-xs:Type>
  <muws-p2-xs:Participant Role="xs:anyURI">
    <muws-p1-xs:ManageabilityEndpointReference/> *
    <muws-p1-xs:ResourceID/> ?
    {any}*
  </muws-p2-xs:Participant>
  <muws-p2-xs:Participant/>+
  <muws-p2-xs:AccessEndpointReference>
    wsa:EndpointReferenceType
  </muws-p2-xs:AccessEndpointReference>?
  {any}*
</muws-p2-xs:Relationship>



The problem I have run into is in defining the ParticipantType
complexType. I have tried the following:

  <xs:complexType name="RelationshipParticipantType">
    <xs:sequence>
      <xs:element ref="muws-p1-xs:ManageabilityEndpointReference"
                  minOccurs="0" maxOccurs="unbounded"/>
      <xs:element ref="muws-p1-xs:ResourceId"
                  minOccurs="0"/>
      <xs:any minOccurs="0" maxOccurs="unbounded"
              namespace="##other" processContents="lax"/>
    </xs:sequence>
    <xs:attribute name="Role" type="xs:anyURI" use="required"/>
    <xs:anyAttribute namespace="##other"/>
  </xs:complexType>

The error I am getting is that the 'any' is causing ambiguity because
there are no required elements - and all optional elements are from the
part1 namespace. All I need is a required element in any namespace to
make it validate.

Does anyone have any suggestions?

Bryan