MD 2013 unknowncomputer.asmx

I am trying to set up web service using MDT 2013 for unknowncomputer.asmx file . 

There are two functions that are not working  - GetADSite and GetAssingnedSite.  (Other three SCCM functions are working fine.)

However if I install Maik Koster web service version 7.3 and use ad.asmx , I get AD site without any problem. 

I am at loss as to what is causing this ..

This is being on Server 2012 R2