What's your source.list look like?

Here's mine as of this minute:

deb http://ftp.ussg.iu.edu/linux/ubuntu/ feisty restricted universe multiverse main
deb http://ftp.ussg.iu.edu/linux/ubuntu/ feisty-updates restricted universe multiverse main
deb http://ftp.ussg.iu.edu/linux/ubuntu/ feisty-security restricted universe multiverse main
deb http://ftp.ussg.iu.edu/linux/ubuntu/ feisty-proposed restricted multiverse universe main
deb http://ftp.ussg.iu.edu/linux/ubuntu/ feisty-backports restricted multiverse universe main
deb http://archive.canonical.com/ubuntu feisty-commercial main
deb http://ubuntu.beryl-project.org feisty main