SharedAccess_NAT problems

[Quark Fusion]

On my system SharedAccess_NAT produces a lot of errors, like 31003, 31004, 30013, 34005, 34001 errors in Event Log. And sometimes configuration of ICS isn't working (while already turned on ICS work), i.e. when I try to turn off and turn on again ICS on network adapter turn on operation fails with null error or similar. At same time svchost.exe can crash also killing other services.

DNS proxy (where that service is?) sometimes stop working and my second PC can't resolve DNS names.

CPU is stable, tested with Prime95 and Folding@home running 24/7 without errors.

I must admit that I apply hack to tcpip.sys since without it ICS totally kills new connections when 2 PC attempt to communicate with p2p networks.

I'm running Vista Ultimate x64 Service Pack 1, Kaspersky Internet Security 8.0. System also have 3 physical (1 disconnected) and 2 virtual (vmware) network adapters. DEP is enabled for all programs and services.

What is proper way to enable ICS with unlimited connections or Vista Ultimate isn't capable of that?