When the server generates a webservice answer that contains special signs like "&" this character is not converted to "&" as expected.
Just imagine a company's name like "Tools & Co." - it would be transferred to the client exactly like this, as you can see in the tcpmon snippet:
<ns1:mndname>AK & Co KG</ns1:mndname>
The parser on the client side fails as it interpretes "&" as starter of a "&something;" construct and does not expect the " " as next char after "&".
The WS requests from the client to the server are formatted correctly ,