我正在尝试更新 Debian 6 服务器，但在以下输出后出现一些错误sudo aptitude update：
Ign http://archive.debian.org oldstable Release.gpg
Ign http://archive.debian.org/debian/ oldstable/contrib Translation-en
Ign http://archive.debian.org/debian/ oldstable/main Translation-en
Ign http://archive.debian.org/debian/ oldstable/non-free Translation-en
Ign http://archive.debian.org oldstable Release
Hit http://ftp.debian.org squeeze-updates Release.gpg
Ign http://ftp.debian.org/debian/ squeeze-updates/contrib Translation-en
Ign http://ftp.debian.org/debian/ squeeze-updates/main Translation-en
Ign http://ftp.debian.org/debian/ squeeze-updates/non-free Translation-en
Ign http://archive.debian.org oldstable/main amd64 Packages
Hit http://ftp.debian.org squeeze-updates Release
Ign http://archive.debian.org oldstable/contrib amd64 Packages
Ign http://archive.debian.org oldstable/non-free amd64 Packages
Ign http://archive.debian.org oldstable/main amd64 Packages
Ign http://archive.debian.org oldstable/contrib amd64 Packages
Hit http://ftp.debian.org squeeze-updates/main amd64 Packages/DiffIndex
Hit http://security.debian.org squeeze/updates Release.gpg
Ign http://security.debian.org/ squeeze/updates/contrib Translation-en
Ign http://security.debian.org/ squeeze/updates/main Translation-en
Ign http://security.debian.org/ squeeze/updates/non-free Translation-en
Ign http://archive.debian.org oldstable/non-free amd64 Packages
Hit http://ftp.debian.org squeeze-updates/contrib amd64 Packages
Hit http://ftp.debian.org squeeze-updates/non-free amd64 Packages
Err http://archive.debian.org oldstable/main amd64 Packages
404 Not Found [IP: 206.12.19.126 80]
Err http://archive.debian.org oldstable/contrib amd64 Packages
404 Not Found [IP: 206.12.19.126 80]
Err http://archive.debian.org oldstable/non-free amd64 Packages
404 Not Found [IP: 206.12.19.126 80]
Hit http://security.debian.org squeeze/updates Release
Hit http://security.debian.org squeeze/updates/main amd64 Packages
Hit http://security.debian.org squeeze/updates/contrib amd64 Packages
Hit http://security.debian.org squeeze/updates/non-free amd64 Packages
这是我的sources.list：
deb http://archive.debian.org/debian oldstable main contrib non-free
deb http://ftp.debian.org/debian/ squeeze-updates main contrib non-free
deb http://security.debian.org/ squeeze/updates main contrib non-free
这个来源是从http://debgen.simplylinux.ch/生成的
怎么了？