Can't connect to update servers

When I want to install new program, I can't connect to update servers. When I press button "Choose best server" and it choose one, I can use it several minutes. But in several minutes after this or after reboot I can't connect to this server without scanning again all mirrors about best server. I'm really bored of this trouble. Please, help me!
Here's my ifconfig output:
eth0 Link encap:Ethernet HWaddr 00:18:F3:9F:0D:5C
          inet addr:192.168.1.2 Bcast:192.168.1.255 Mask:255.255.255.0
          UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
          RX packets:2833 errors:0 dropped:0 overruns:0 frame:0
          TX packets:2268 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000
          RX bytes:3340333 (3.1 MB) TX bytes:387097 (378.0 KB)
          Interrupt:18 Base address:0x6000

lo Link encap:Local Loopback
          inet addr:127.0.0.1 Mask:255.0.0.0
          UP LOOPBACK RUNNING MTU:16436 Metric:1
          RX packets:0 errors:0 dropped:0 overruns:0 frame:0
          TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:0
          RX bytes:0 (0.0 b) TX bytes:0 (0.0 b)

And here's my current sources.list:

# deb cdrom:[Ubuntu 7.10 _Gutsy Gibbon_ - Release i386 (20071016)]/ gutsy main restricted
# See http://help.ubuntu.com/community/UpgradeNotes for how to upgrade to
# newer versions of the distribution.

# Line commented out by installer because it failed to verify:
# deb http://ru.archive.ubuntu.com/ubuntu/ gutsy main restricted
# Line commented out by installer because it failed to verify:
# deb-src http://ru.archive.ubuntu.com/ubuntu/ gutsy main restricted

## Major bug fix updates produced after the final release of the
## distribution.
# Line commented out by installer because it failed to verify:
# deb http://ru.archive.ubuntu.com/ubuntu/ gutsy-updates main restricted
# Line commented out by installer because it failed to verify:
# deb-src http://ru.archive.ubuntu.com/ubuntu/ gutsy-updates main restricted

## 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
## universe WILL NOT receive any review or updates from the Ubuntu security
## team.
# Line commented out by installer because it failed to verify:
# deb http://ru.archive.ubuntu.com/ubuntu/ gutsy universe
# Line commented out by installer because it failed to verify:
# deb-src http://ru.archive.ubuntu.com/ubuntu/ gutsy universe
# Line commented out by installer because it failed to verify:
# deb http://ru.archive.ubuntu.com/ubuntu/ gutsy-updates universe
# Line commented out by installer because it failed to verify:
# deb-src http://ru.archive.ubuntu.com/ubuntu/ gutsy-updates universe

## 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.
# Line commented out by installer because it failed to verify:
# deb http://ru.archive.ubuntu.com/ubuntu/ gutsy multiverse
# Line commented out by installer because it failed to verify:
# deb-src http://ru.archive.ubuntu.com/ubuntu/ gutsy multiverse
# Line commented out by installer because it failed to verify:
# deb http://ru.archive.ubuntu.com/ubuntu/ gutsy-updates multiverse
# Line commented out by installer because it failed to verify:
# deb-src http://ru.archive.ubuntu.com/ubuntu/ gutsy-updates multiverse

## 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 http://ftp.ds.karen.hj.se/pub/os/linux/ubuntu/ gutsy-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 gutsy partner
# deb-src http://archive.canonical.com/ubuntu gutsy partner

# Line commented out by installer because it failed to verify:
# deb http://security.ubuntu.com/ubuntu gutsy-security main restricted
# Line commented out by installer because it failed to verify:
# deb-src http://security.ubuntu.com/ubuntu gutsy-security main restricted
# Line commented out by installer because it failed to verify:
# deb http://security.ubuntu.com/ubuntu gutsy-security universe
# Line commented out by installer because it failed to verify:
# deb-src http://security.ubuntu.com/ubuntu gutsy-security universe
# Line commented out by installer because it failed to verify:
# deb http://security.ubuntu.com/ubuntu gutsy-security multiverse
# Line commented out by installer because it failed to verify:
deb http://ftp.ds.karen.hj.se/pub/os/linux/ubuntu/ gutsy main universe restricted multiverse
deb http://security.ubuntu.com/ubuntu/ gutsy-security universe main multiverse restricted
deb http://ftp.ds.karen.hj.se/pub/os/linux/ubuntu/ gutsy-updates universe main multiverse restricted
deb http://ftp.ds.karen.hj.se/pub/os/linux/ubuntu/ gutsy-proposed universe main multiverse restricted
# deb-src http://security.ubuntu.com/ubuntu gutsy-security multiverse