SOAP W3C Recommendation

Hello everyone,

I am trying to consume a webservice whose input parameters follow this schema definition

<s:element name="Insert">
    <s:complexType>
        <s:sequence>
              <s:element minOccurs="0" maxOccurs="1" name="dataObject" type="s:string" /> 
              <s:element minOccurs="0" maxOccurs="1" name="xmlPayload" type="s:string" /> 
          </s:sequence>
  </s:complexType>

as I generate the correspondent SOAP message, I get an error saying that my message isn't W3C conform, because tags beginning with "xml" aren't allowed. I looked at the specification but I didn't find this restriction. Is it really against the specification to have a tag beginning with "xml" (in this case xmlPayload) in your SOAP message ?

Cheers Nicolas Fonnegra