Soapui 4.5.1 integrated auth proxy

Hi, i'm trying to resolve an issue concerning soapui 4.5.1 and proxy authentication. in our company is necessary the use of proxies and we use microsoft forefront tmg. we've basic proxies and integrated authentication proxies, with both the result is the same. for now the workaround was use soapUI 4.0.0 or 4.0.1 with burp suite, with it is possible the use of ntlmv2 authentication. soapUI 4.5.1 also doesn't work with this solution. in attach is the error log. if more information is needed please inform.

thanks