SOAP port uses a non-standard SOAP 1.2 binding

Question

I am using the jaxws maven plugin to generate webservices access classes. During the generation the following warning is printed:

[WARNING] SOAP port "MyServicePort" uses a non-standard SOAP 1.2 binding. line XXX of http://...?wsdl

By adding an additional argument (-extension) I got it to work however I am wondering what this error is about? SOAP 1.2 Binding seems official to me - so whats the problem?

The namespace defition of the wsdl is like this:

<?xml version="1.0" encoding="UTF-8"?>
<wsdl:definitions name="FooServerInvoker" 

targetNamespace="http://ws.server.foo.com/" 
xmlns:ns1="http://schemas.xmlsoap.org/soap/http" 
xmlns:soap="http://schemas.xmlsoap.org/wsdl/soap/" 
xmlns:soap12="http://schemas.xmlsoap.org/wsdl/soap12/" 
xmlns:tns="http://ws.server.jadice.levigo.com/" 
xmlns:wsdl="http://schemas.xmlsoap.org/wsdl/" 
xmlns:xsd="http://www.w3.org/2001/XMLSchema">

The problem is mentioned here where you can find an example wsdl if you want to try out.