Windows 8 & Cside Client (Navision Dynamics NAV 5.0)

Hi,

I just installed a new computer for a client, the first computer with Windows 8. Installing the Cside client exactly as I usually did for all prior versions of WIndows and opening a database (WIndows Authentication / TCP) gives the error:TCP/IP Error ECONNREFUSED.

Is this related to Windows 8, or something else. I now see here http://nav.dk/content/microsoft-dynamics-nav-2013-compatiblity-microsoft-windows-8-and-microsoft-windows-server-20 that only from 2009 R2 and up supports Windows 8.

I am not a Navision specialist, but a Windows & networking specialist. Please help.