I just recently installed Ubuntu 11.04 on my desktop, and I only entered in one password during the install process. This password works to log into the machine, run updates etc. When I open up the terminal, and try to use su and I enter in the same password... I get an Authentication failure.
I've booted my computer up in recovery mode, and reset the password from the command line, but I'm still getting the same authentication error.
If anyone could help me out, I would appreciate it.