Ubuntu: Last nail in the coffin

I decided to give Ubuntu one more try and do a fresh install of Feisty (the most recent version I had). The nv driver again proved worthless by only giving me 800x600 but the restricted drivers manager correctly installed the binary drivers. But I notice something weird with 'sudo' when I was trying to set up my SVN repos. I did a 'sudo svn-admin create /home/svn-code', but nothing happened. I tried a 'sudo mkdir foo' and it didn't make a directory. 'sudo passwd root' didn't prompt me for a new password. What's going on? I reboot the machine, figuring it might be because it was because I upgraded some fundamental packages. I reboot, log back in, and now everything from my System->Administration menu is gone. I can't sudo, can't log in as root, can't do anything. I'm locked out of my own machine! Ubuntu is now officially banned from any machine I have control over.