Straight after reinstalling Ubuntu 12.10, I did a couple of sudo commands and exited. Now, as soon as I open a terminal, I'm asked for my sudo password. I have to enter a wrong password three times to get a user terminal prompt. This hasn't happened on any previous Ubuntu installation.
Restarting the computer made no difference. I searched the web and the forums without getting an answer probably because I can't think of the right keywords. Can anyone please help? Thanks.