disappearing network

DUN works great from home net with 4
systems over TCP/IP with hub. Trying to get ICS going. But, local net disappears
when DUN connected. Can ping locally
with DUN off but not when DUN connected.
Cannot ping remotely from clients when
DUN connected. ICS reports other systems
using net connection. Can see DHCP host
and reconfig at all times from clients.
I think Internet Connection Wizard has a
stuck registry key related to “disable
File and Printer Sharing while connected
to the internet”. Have tried many hacks
including removing winsock2 key and all
protocols and reinstalling. Ant ideas
before I reinstall my network?