A: 

One thing I noticed is that there is a faultcode value in the SoapFault Object:

[faultcode] => soap-env:Client.InvalidEbXmlMessage

So that may be a useful avenue to start debugging.

I tried comparing the structure of your EbXmlMessage to the XSD and the schema documentation, but I couldn't see any obvious reason that it was declared invalid.

JSchaefer
A: 

Have you tried changing the Content-type header to text/xml?