Seu proxy está jogando você:
wget http://security.ubuntu.com/ubuntu/pool/main/l/linux-firmware/linux-firmware_1.79.6_all.deb
--2013-09-24 09:39:08-- http://security.ubuntu.com/ubuntu/pool/main/l/linux-firmware/linux-firmware_1.79.6_all.deb
Resolving localhost (localhost)... ::1, ::1, 127.0.0.1
Connecting to localhost (localhost)|::1|:3128... connected.
Proxy request sent, awaiting response... 200 OK
Length: 23217718 (22M) [application/x-debian-package]
Saving to: ‘linux-firmware_1.79.6_all.deb’
100%[======================================>] 23,217,718 153KB/s in 3m 3s
2013-09-24 09:42:10 (124 KB/s) - ‘linux-firmware_1.79.6_all.deb’ saved [23217718/23217718]
Só não use o proxy e tudo ficará bem. wget --no-cache
ou excluir todo o seu cache de proxy deve fazer o trabalho.