> Where did you set "Allow other network users to connect through this computer's internet connection" - in virtualbox????
Start->Control Panel->Network Connections
Right-click properties on I *think* Wireless Network Connection
and go to the Advanced Tab.
BUT, I think it was "For the Ubuntu guest, I got the DNS IPs from the AT&T client, and in the guest in IP4 Settings changed to "Automatic DHCP (Addresses Only)" and then inserted the DNS IPs. " that made the difference. As a matter of fact, something turned the "allow other network users to connect" thing off, and, if I set the DNS correctly in the Ubuntu VirtualBox guest, it works. Be sure to, after you have set the DNS address, to refresh the network connection... click on the little network icon above the desktop, and choose the "Auto eth4" or whatever it is you have there.
I have to set the DNS thing every time I restart. I think this is a known issue, with a kind of ugly fix if you want to put in a bit of work. But someone with some knowledge would have to help with that.
Good luck. Really frustrating, I know. Though, geez, I sure do like VirtualBox. And Ubuntu... trying to resist the urge to install it as my default OS.