I have an old Dell Latitude D620 that I installed Ubuntu 12.04 on. I had originally installed the Ubuntu 12.04 Server configuration, than added in the desktop stuff later with "apt-get install ubuntu-desktop".
If I have a hard-wired connection, the WiFi also works, at least as far as seeing my WiFi SID and authenticating via WPA. But, if I disconnect the wired connection and reboot, I don't get any networking at all.
During boot, I get console messages saying, "Waiting for network configuration...", followed by "Waiting up to 60 more seconds for network configuration...". When the system finally comes up, ifconfig shows eth0 UP, and lists wan0, but it's not UP. There's no WiFi widget in my toolbar. And, if I open the Network control panel, I get a frowny face and "The system network service are not compatible with this version".
Any idea what's wrong?