Strange Error calling method of wsdl based SOAP client

I'm talking to the Membersuite SOAP api.  They have a Get() method
and a Save() method for objects.  I call Get(), and get an object
back representing an individual.  I pass it back to Save() and I
get this:

Fatal error: Uncaught SoapFault exception: [a:DeserializationFailed]
The formatter threw an exception while trying to deserialize the message:
     There was an error while trying to deserialize parameter http://membersuite.com/contracts:objectToSave.

The InnerException message was
     'Element Value from namespace http://schemas.datacontract.org/2004/07/MemberSuite.SDK.Types
     cannot have child contents to be deserialized as an object. Please use XmlNode[] to deserialize this pattern of XML.'.
     Please see InnerException for more details. in /home/toby/public_html/membersuite/-:115
     Stack trace:
     #0 /home/toby/public_html/membersuite/-(115): SoapClient->__soapCall('Save', Array, NULL, Array, Array)
     #1 /home/toby/public_html/membersuite/-(18): Membersuite->call('Save', Array)
     #2 {main}
       thrown in /home/toby/public_html/membersuite/- on line 115


The whole store with source code is here:

     http://register.rcsreg.com/r2/membersuite

Thanks for any help.  I've been working on this
for over a month now.

Tobiah