Hello jbear123：）

Your xml contents aren't right：

1）Without ending tags for web:xxx。

2）Without ending tags for Searchresponse。

And what I'm thinking is that your web isn't declared as a Namespace。Plz redefine it and have a try。

Sample：

【xml】

<soapenv:Envelope
xmlns:soapenv="http://soapenv/"
xmlns:xsd="http://XXX"
xmlns:xsi="http://XXX">
<soapenv:Body >
<Info xmlns="http://Info">
<V>123</V>
<O>456</O>
<M>789</M>
</Info>
</soapenv:Body>
</soapenv:Envelope>

【result】

XPathNavigator xPathNavigator = new XPathDocument(xmlStream).CreateNavigator();
XmlNamespaceManager nsmgr = new XmlNamespaceManager(xPathNavigator.NameTable);
nsmgr.AddNamespace("mySpaceSoapenv", "http://soapenv/");
nsmgr.AddNamespace("mySpaceInfo", "http://Info");

XPathNodeIterator nodes = xPathNavigator.Select("/mySpaceSoapenv:Envelope/mySpaceSoapenv:Body/mySpaceInfo:mobileEmailBoxInfo/mySpaceInfo:Version", nsmgr);