Upgrade to ubuntu 11.10 - cannot get back into system i get: "setting up network information" message

After updating to 11.10 from the last version, I am unable to access the system. I can log in but never get any window. I was using Kubuntu. I switched to default Gnome, but most menu entries do not have associated programs. I cannot set up anything. I can not get into the system in recovery mode, log on the internet to try to fix with updates, or return to a previous version.

Any ideas or steps to take to get the system back to a point I can try to fix something?

The main error I receive is "setting up network information" and "waiting up to 60 seconds to configure network" otherwise, a black screen with a working mouse cursor.