After having an endless supply of internet connection sharing problems with Windows Live OneCare, I finally managed to resolve the problem - just in the same way I did with the IPv6 Firewall service thing which I posted on the Dell Community Forums - trial and error!
Anyway... for anyone who has the same problem and just happens to type the right keywords in Google will find this useful: Go to the OneCare settings > Firewall > Ports and Protocols and click Add.
- Share internet: TCP/UDP. Port range 139 to 139. For connections Inbound [local ports]. Scope Internet.
- Share files: UDP. Port range 53 to 53. For connections Inbound [local ports]. Scope Internet.
So there we are.
However, a newsletter from CNET enlightened me wih the fact that OneCare recently failed completely to protect against recent internet threats - so I might go back to ZoneAlarm?! Any other suggestions, anyone?