I did a regular update of Ubuntu 11.10 yesterday night and it didn't require a restart.
After the update finished I still had connection (wired). But, today, when I tried to go to Google and other sites, there was no connection. Network manager is installed and it said no connection found. I've checked the cable and nothing seems to be wrong.
How can I get my connection back? It works fine on Windows (from which I'm writing this).