I've been using Ubuntu 15.04 for a while with my password, so far so good (I'm the only user and root). But I wanted to change my password and tried to do that throuth terminal withsudo passwd. It asks me for my new password and than tell me the pw was successfully updated. The point is, my password doesn't change, it is the same old one. The new one doesn't work, it looks as if I've done nothing. What is that and how do I fix?
Grateful.