I enabled the root password a while back. But not three days ago. I'm using Ubuntu 12.04 with latest updates. My laptop is Vostro 3500
For about three day ago, I saw the symptoms. And those are, When I use sudo on terminal, it doesn't ask for my password. It just do it. Eg. sudo apt-get update just execute.
I use cpufreq utilities and their unity indicator to change cpu scaling. It didn't ask for my password. But, now window appear to ask my password when I want to change cpu scaling mode. (ondemand to power save etc. ) (password windows is same as when I open synaptic package manager.).