i have upgrade to ubuntu 12.10 from ubuntu 12.04 after that it is not updating software updater gives the following error :

W:Failed to fetch http://archive.canonical.com/ubuntu/dists/precise/Release.gpg  Unable to connect to 10.4.42.15:8080:
W:Failed to fetch http://extras.ubuntu.com/ubuntu/dists/quantal/Release.gpg  Unable to connect to 10.4.42.15:8080:
W:Failed to fetch http://us.archive.ubuntu.com/ubuntu/dists/quantal/Release.gpg  Unable to connect to 10.4.42.15:8080:
W:Failed to fetch http://us.archive.ubuntu.com/ubuntu/dists/quantal-updates/Release.gpg  Unable to connect to 10.4.42.15:8080:
W:Failed to fetch http://us.archive.ubuntu.com/ubuntu/dists/quantal-backports/Release.gpg Unable to connect to 10.4.42.15:8080:
W:Failed to fetch http://us.archive.ubuntu.com/ubuntu/dists/quantal-security/Release.gpg Unable to connect to 10.4.42.15:8080:
W:Failed to fetch http://us.archive.ubuntu.com/ubuntu/dists/quantal-proposed/Release.gpg Unable to connect to 10.4.42.15:8080:
W:Failed to fetch http://us.archive.ubuntu.com/ubuntu/dists/quantal/restricted/source/Sources Unable to connect to 10.4.42.15:8080:
W:Failed to fetch http://us.archive.ubuntu.com/ubuntu/dists/quantal/main/source/Sources  Unable to connect to 10.4.42.15:8080:
W:Failed to fetch http://us.archive.ubuntu.com/ubuntu/dists/quantal/multiverse/source/Sources Unable to connect to 10.4.42.15:8080:
W:Failed to fetch http://us.archive.ubuntu.com/ubuntu/dists/quantal/universe/source/Sources Unable to connect to 10.4.42.15:8080:
  :
W:Failed to fetch http://us.archive.ubuntu.com/ubuntu/dists/quantal-proposed/universe/i18n/Translation-en Unable to connect to 10.4.42.15:8080:
E:Some index files failed to download. They have been ignored, or old ones used instead.

along with this i am not able to install any thing from software center , it just asks to use this source and after that it just keeps on quering software sources and nothing happens after that

plz help me out , this 12.10 has became a great problem for me and forgive for my poor engish