problema add/remove applications con ubuntu 8.10

[lukas4]

hola que tal, ya estuve investigando por todos lados y nunca esta de mas pedir algo de ayuda extra, tengo un problema al querer instalar CUALQUIER aplicacion en ubuntu, ya sea desde add/remove applications o desde la consola, en primera en add/remove applications, las aplicaciones de canonical, todas, pero TODAS dicen este mensaje

cannot be installed on your computer type (i386). Either the application requires special hardware features or the vendor decided to not support your computer type.

y cuando le seleccione para que me muestre todas las aplicaciones opensource me sale este error (en este caso Amaya):

Failed to fetch http://security.ubuntu.com/ubuntu/di...86/Packages.gz 407 Proxy Authentication Required
Failed to fetch http://mx.archive.ubuntu.com/ubuntu/...86/Packages.gz 407 Proxy Authentication Required
Failed to fetch http://mx.archive.ubuntu.com/ubuntu/...86/Packages.gz 407 Proxy Authentication Required
Failed to fetch http://mx.archive.ubuntu.com/ubuntu/...rce/Sources.gz 407 Proxy Authentication Required
Failed to fetch http://security.ubuntu.com/ubuntu/di...86/Packages.gz 407 Proxy Authentication Required
Failed to fetch http://security.ubuntu.com/ubuntu/di...rce/Sources.gz 407 Proxy Authentication Required
Failed to fetch http://security.ubuntu.com/ubuntu/di...rce/Sources.gz 407 Proxy Authentication Required
Failed to fetch http://security.ubuntu.com/ubuntu/di...86/Packages.gz 407 Proxy Authentication Required
Failed to fetch http://security.ubuntu.com/ubuntu/di...rce/Sources.gz 407 Proxy Authentication Required
Failed to fetch http://security.ubuntu.com/ubuntu/di...86/Packages.gz 407 Proxy Authentication Required
Failed to fetch http://security.ubuntu.com/ubuntu/di...rce/Sources.gz 407 Proxy Authentication Required
Failed to fetch http://mx.archive.ubuntu.com/ubuntu/...rce/Sources.gz 407 Proxy Authentication Required
Failed to fetch http://mx.archive.ubuntu.com/ubuntu/...86/Packages.gz 407 Proxy Authentication Required
Failed to fetch http://mx.archive.ubuntu.com/ubuntu/...rce/Sources.gz 407 Proxy Authentication Required
Failed to fetch http://mx.archive.ubuntu.com/ubuntu/...86/Packages.gz 407 Proxy Authentication Required
Failed to fetch http://mx.archive.ubuntu.com/ubuntu/...rce/Sources.gz 407 Proxy Authentication Required
Failed to fetch http://mx.archive.ubuntu.com/ubuntu/...86/Packages.gz 407 Proxy Authentication Required
Failed to fetch http://mx.archive.ubuntu.com/ubuntu/...86/Packages.gz 407 Proxy Authentication Required
Failed to fetch http://mx.archive.ubuntu.com/ubuntu/...rce/Sources.gz 407 Proxy Authentication Required
Failed to fetch http://mx.archive.ubuntu.com/ubuntu/...rce/Sources.gz 407 Proxy Authentication Required
Failed to fetch http://mx.archive.ubuntu.com/ubuntu/...86/Packages.gz 407 Proxy Authentication Required
Failed to fetch http://mx.archive.ubuntu.com/ubuntu/...rce/Sources.gz 407 Proxy Authentication Required
Failed to fetch http://mx.archive.ubuntu.com/ubuntu/...86/Packages.gz 407 Proxy Authentication Required
Failed to fetch http://mx.archive.ubuntu.com/ubuntu/...rce/Sources.gz 407 Proxy Authentication Required
Some index files failed to download, they have been ignored, or old ones used instead.

desde un principio configure el proxy y todo ese asunto, y al estar investigando encontre que debo modificar el archivo /etc/bash.bashrc (junto con otros mas) y poner un codigo, especificando esto:

export http_proxy=http://username:[email protected]:port/
export https_proxy=http://username:[email protected]:port/
export ftp_proxy=http://username:[email protected]:port/

pero ya al hacerlo, no me deja guardarlo me dice esto:

Could not save the file /etc/bash.bashrc.
You do not have the permissions necessary to save the file. Please check that you typed the location correctly and try again.

alguna idea de que podria ser, como resolver algo o todo eso?

nota: trate de editarlo desde el editor de texto de ubuntu, ya que no se como usar vi en la consola xP
alguna idea de como resolver algo o todo lo anterior, de antemano, gracias