I'm not set up as root and don't want to be. But sometimes /not always/ but sometimes when I try to run a sudo command, I'm asked for my password. I type in my user password, since I don't think I have a root pw, not being root, right?) and the password isn't accepted. Why does this happen? For instance, I tried a sudo command and got this terminal response: "user password accepted on login but rejected on terminal"