According to a thread in the forum (http://ubuntuforums.org/showthread.php?t=1491242&highlight=eth0+network+manager), my disabled networking was probably caused after a hibernate locked up the machine and I had to physically reboot it. Unfortunately, the solution in the thread is for Ubuntu, not KUbuntu which is what I'm running.
According to a thread in the forum (http:// ubuntuforums. org/showthread. php?t=1491242& highlight= eth0+network+ manager), my disabled networking was probably caused after a hibernate locked up the machine and I had to physically reboot it. Unfortunately, the solution in the thread is for Ubuntu, not KUbuntu which is what I'm running.