When I run the update manager, it tells me to check my internet connnection. From the command line, I get the following when I run sudo apt-get update.
Err http://extras.ubuntu.com quantal Release.gpg
Unable to connect to extras.ubuntu.com:http:
Ign http://extras.ubuntu.com quantal Release
Ign http://extras.ubuntu.com quantal/main Sources/DiffIndex
Ign http://extras.ubuntu.com quantal/main i386 Packages/DiffIndex
Err http://extras.ubuntu.com quantal/main Translation-en_US
Unable to connect to extras.ubuntu.com:http:
Err http://extras.ubuntu.com quantal/main Translation-en
Unable to connect to extras.ubuntu.com:http:
Err http://extras.ubuntu.com quantal/main Sources
Unable to connect to extras.ubuntu.com:http:
Err http://extras.ubuntu.com quantal/main i386 Packages
Unable to connect to extras.ubuntu.com:http:
W: Failed to fetch http://ppa.launchpad.net/gezakovacs/ppa/ubuntu/dists/quantal/main/source/Sources 404 Not Found
W: Failed to fetch http://ppa.launchpad.net/gezakovacs/ppa/ubuntu/dists/quantal/main/binary-i386/Packages 404 Not Found
W: Failed to fetch http://extras.ubuntu.com/ubuntu/dists/quantal/Release.gpg Unable to connect to extras.ubuntu.com:http:
W: Failed to fetch http://extras.ubuntu.com/ubuntu/dists/quantal/main/i18n/Translation-en_US Unable to connect to extras.ubuntu.com:http:
W: Failed to fetch http://extras.ubuntu.com/ubuntu/dists/quantal/main/i18n/Translation-en Unable to connect to extras.ubuntu.com:http:
W: Failed to fetch http://extras.ubuntu.com/ubuntu/dists/quantal/main/source/Sources Unable to connect to extras.ubuntu.com:http:
W: Failed to fetch http://extras.ubuntu.com/ubuntu/dists/quantal/main/binary-i386/Packages Unable to connect to extras.ubuntu.com:http:
E: Some index files failed to download. They have been ignored, or old ones used instead.