Synaptics, Repository cannot update files, Ubuntu 10

I used ubuntu 10, the synaptics, repository always get problem when update. I chose repository -> ubuntu software -> and tick "Canonical-supported open Source software (main)" -> then close -> and then reload. After reload, I found the problem shown: the title: Could not download all repository indexes. the content: Failed to fetch http://archive.ubuntu.com/dists/maverick/binary-i386/Packages.gz 404 No Found.
I can surf the net. It may not be proxy problem. Only the problem is the synaptics and repository cannot update the software. It seems the synaptics cannot connect to Internet.
Below is my /etc/apt/sources.list content.

Anyone will have any good comments and Opinion to solve this problem?
Thanks in advance.

#
# deb cdrom:[Ubuntu-Server 10.10 _Maverick Meerkat_ - Release i386 (20101007)]/ maverick main restricted

# deb cdrom:[Ubuntu-Server 10.10 _Maverick Meerkat_ - Release i386 (20101007)]/ maverick main restricted
# See http://help.ubuntu.com/community/UpgradeNotes for how to upgrade to
# newer versions of the distribution.

## Major bug fix updates produced after the final release of the
## distribution.

## N.B. software from this repository is ENTIRELY UNSUPPORTED by the Ubuntu
## team. Also, please note that software in universe WILL NOT receive any
## review or updates from the Ubuntu security team.

## N.B. software from this repository is ENTIRELY UNSUPPORTED by the Ubuntu
## team, and may not be under a free licence. Please satisfy yourself as to
## your rights to use the software. Also, please note that software in
## multiverse WILL NOT receive any review or updates from the Ubuntu
## security team.

## Uncomment the following two lines to add software from the 'backports'
## repository.
## N.B. software from this repository may not have been tested as
## extensively as that contained in the main release, although it includes
## newer versions of some applications which may provide useful features.
## Also, please note that software in backports WILL NOT receive any review
## or updates from the Ubuntu security team.
# deb-src http://us.archive.ubuntu.com/ubuntu/ maverick-backports main restricted universe multiverse

## Uncomment the following two lines to add software from Canonical's
## 'partner' repository.
## This software is not part of Ubuntu, but is offered by Canonical and the
## respective vendors as a service to Ubuntu users.
deb http://archive.canonical.com/ubuntu maverick partner
deb-src http://archive.canonical.com/ubuntu maverick partner

## Uncomment the following two lines to add software from Ubuntu's
## 'extras' repository.
## This software is not part of Ubuntu, but is offered by third-party
## developers who want to ship their latest software.
deb http://extras.ubuntu.com/ubuntu maverick main
deb-src http://extras.ubuntu.com/ubuntu maverick main

deb http://archive.ubuntu.com/ubuntu maverick main universe restricted multiverse
deb-src http://archive.ubuntu.com/ubuntu maverick universe main multiverse restricted #Added by software-properties
deb http://security.ubuntu.com/ubuntu/ maverick-security universe main multiverse restricted
deb-src http://security.ubuntu.com/ubuntu/ maverick-security universe main multiverse restricted
deb http://archive.ubuntu.com/ubuntu maverick-updates universe main multiverse restricted
deb-src http://archive.ubuntu.com/ubuntu maverick-updates universe main multiverse restricted