Sounds like root's name got changed. What distro are you using? You can probably recover root without having to mess up your config.
Just to see, try using Kuser if you have it, and since the system took your root password, it will also so you will be able to get into user config. See if root is infact still called "root". If you can get into Kuser that way, you should be able to get into a "Super User Console" to try to fix what you broke.