Cannot stop host dialling out with ICS

Hello, I bet this is a common problem. I have a network
of two PC's both running XP home. One PC is set up for
ICS the idea being that the other can access the internet
at the same time. Only trouble is the client PC keeps
making the host dial out. I've run the Network
Troubeshooter many times and deactivated the internet
clock. IP and DNS's are set to obtain automatically. I've
turned off all the startup items in System Config. But I
still have the problem. Any ideas gratefully received.

Gary