New to the scene and my first post. I hope this helps you
After many many hours of trying to work out why my silly domain and windows 2008 r2 DC would not allow conx connectivity. I found this, followed it an volia it worked!!!
http://support.exinda.com/topic/how-to-disable-smb-signing-on-windows-servers-to-improve-smb-performance
P.S Make sure your server name does not have any - in it i.e. my-server.mydom
Good luck, I hope this works.