Here's one that will probably take an abolute Linux god to troubleshoot: Whenever I try to log in as any account in Red Hat 9 with the correct password, I get a popup box that says "Authentication failed." If I try an incorrect password, it says "Incorrect username or password. Letters must be typed in the correct case. Please make sure the Caps Lock key is not enabled" below the login box. I am sure that the password is right, because I booted in as root by passing the single parameter to the kernel from the bootloader, and I changed my root password and my user account to password (I made sure caps lock was off and typed it all out with one finger slowly to make sure there were no typos). Even in single-user mode, if I try to use SU (doesn't matter what username I give it), instead of prompting me for a password, it just says "incorrect password" EDIT: Yes, it is my own fault. I made a bunch of changes to the system trying to get the bugger to authenticate to a Windows 2000 ISA server to get out to the internet, but there were a *lot* of changes, and I don't remember what all of them were, so I can't begin to guess at what I did to slaik login security up like this.