unable to connect using software center

hi i'm having the same problem that i had in ubuntu 11.04. i am able to connect to net, browse using the firefox browser. however when go to software center and try to install anything it does not connect. when trying to select - select best server i get the message no suitable download server found. i use the main server and stil no go.
i tried sudo apt-get update in the terminal and this is the message i get.

tijah@tiju:~$ sudo apt-get update
Err http://archive.ubuntu.com precise InRelease

Err http://archive.ubuntu.com precise-updates InRelease

Err http://archive.ubuntu.com precise-backports InRelease

Err http://archive.ubuntu.com precise-security InRelease

Err http://archive.ubuntu.com precise Release.gpg
  Unable to connect to archive.ubuntu.com:http: [IP: 91.189.92.182 80]
Err http://archive.ubuntu.com precise-updates Release.gpg
  Unable to connect to archive.ubuntu.com:http: [IP: 91.189.92.182 80]
Err http://archive.ubuntu.com precise-backports Release.gpg
  Unable to connect to archive.ubuntu.com:http: [IP: 91.189.92.182 80]
Err http://archive.ubuntu.com precise-security Release.gpg
  Unable to connect to archive.ubuntu.com:http: [IP: 91.189.92.182 80]
Err http://ppa.launchpad.net precise InRelease

Err http://ppa.launchpad.net precise Release.gpg
  Unable to connect to ppa.launchpad.net:http:
Err http://archive.canonical.com precise InRelease

Err http://archive.canonical.com precise Release.gpg
  Unable to connect to archive.canonical.com:http: [IP: 91.189.92.150 80]
Err http://extras.ubuntu.com precise InRelease

Err http://extras.ubuntu.com precise Release.gpg
  Unable to connect to extras.ubuntu.com:http:
Reading package lists... Done
W: Failed to fetch http://archive.ubuntu.com/ubuntu/dists/precise/InRelease

W: Failed to fetch http://archive.ubuntu.com/ubuntu/dists/precise-updates/InRelease

W: Failed to fetch http://archive.ubuntu.com/ubuntu/dists/precise-backports/InRelease

W: Failed to fetch http://archive.ubuntu.com/ubuntu/dists/precise-security/InRelease

W: Failed to fetch http://archive.canonical.com/ubuntu/dists/precise/InRelease

W: Failed to fetch http://extras.ubuntu.com/ubuntu/dists/precise/InRelease

W: Failed to fetch http://ppa.launchpad.net/ubuntu-wine/ppa/ubuntu/dists/precise/InRelease

W: Failed to fetch http://archive.ubuntu.com/ubuntu/dists/precise/Release.gpg Unable to connect to archive.ubuntu.com:http: [IP: 91.189.92.182 80]

W: Failed to fetch http://archive.ubuntu.com/ubuntu/dists/precise-updates/Release.gpg Unable to connect to archive.ubuntu.com:http: [IP: 91.189.92.182 80]

W: Failed to fetch http://archive.ubuntu.com/ubuntu/dists/precise-backports/Release.gpg Unable to connect to archive.ubuntu.com:http: [IP: 91.189.92.182 80]

W: Failed to fetch http://archive.ubuntu.com/ubuntu/dists/precise-security/Release.gpg Unable to connect to archive.ubuntu.com:http: [IP: 91.189.92.182 80]

W: Failed to fetch http://ppa.launchpad.net/ubuntu-wine/ppa/ubuntu/dists/precise/Release.gpg Unable to connect to ppa.launchpad.net:http:

W: Failed to fetch http://archive.canonical.com/ubuntu/dists/precise/Release.gpg Unable to connect to archive.canonical.com:http: [IP: 91.189.92.150 80]

W: Failed to fetch http://extras.ubuntu.com/ubuntu/dists/precise/Release.gpg Unable to connect to extras.ubuntu.com:http:

W: Some index files failed to download. They have been ignored, or old ones used instead.

i am currently using ubuntu 12.04 lts - any help would be very much appreciated. please note i'm a newbie to ubuntu.
thanks