NTLM v2 Authentication

I am trying to get version 5.2.1 to work at a customer site, but am having trouble getting NTLM v2 authentication to work.  I always get a 401 error back from the WCF SOAP service, unless I use Fiddler as a proxy.  If Fiddler is in the chain, everything works as expected. 

Does the Open Source version above support NTLM authentication?  What steps should I take to get SOAP UI to work without Fiddler.

Regards

Tom