Ubuntu 10.04 update-manager error

[KingNothing]

I tried to install Cairo from the "Synaptic Package Manager" but i was unsuccessful, also i cant open the "Synaptic Package Manager" or "Update Manager" without getting an error. I have posted both the errors below, please can someone please tell me how to fix this problem. Thanks.

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"Synaptic Package Manager" error:

An error occurred

The following details are provided:

E: Type 'Cairo-Dock-PPA-Stable' is not known on line 55 in source list /etc/apt/sources.list
E: The list of sources could not be read.
Go to the repository dialog to correct the problem.
E: _cache->open() failed, please report.

================================================== ===========

"Update Manager" error:

Could not initialize the package information

An unresolvable problem occurred while initializing the package information.

Please report this bug against the 'update-manager' package and include the following error message:

'E:Type 'Cairo-Dock-PPA-Stable' is not known on line 55 in source list /etc/apt/sources.list, E:The list of sources could not be read.'

[devils casper]

Hi and Welcome !

Something is wrong in line 55 having Cairo-Dock-PPA-Stable of sources.list file. Put # sign before that line.
Press Alt+F2 and type this

gksu gedit /etc/apt/sources.list

Above code will open sources.list file in Gedit with root privileges. Put # before line no. 55. Save file and try running Synaptic Package Manager again.

In case it doesn't work, attach sources.list file in your post.

[KingNothing]

Thanks for the quick reply

Both the errors seem to be gone however i am getting the same error for both "Synaptic Package Manager" and "Update Manager":

Could not download all repository indexes

The repository may no longer be available or could not be contacted because of network problems. If available an older version of the failed index will be used. Otherwise the repository will be ignored. Check your network connection and ensure the repository address in the preferences is correct.

Lists directory /var/lib/apt/lists/partial is missing.

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Also here is source.list file you requested:

1.#deb cdrom:[Ubuntu 10.04.1 LTS _Lucid Lynx_ - Release amd64 (20100816.1)]/ lucid main restricted
2.# See hxxp://help.ubuntu.com/community/UpgradeNotes for how to upgrade to
3.# newer versions of the distribution.
4.
5.deb [hxxp://ca.archive.ubuntu.com/ubuntu/]Index of /ubuntu] lucid main restricted
6.deb-src [hxxp://ca.archive.ubuntu.com/ubuntu/]Index of /ubuntu] lucid main restricted
7.
8.## Major bug fix updates produced after the final release of the
9.## distribution.
10.deb [hxxp://ca.archive.ubuntu.com/ubuntu/]Index of /ubuntu] lucid-updates main restricted
11.deb-src [hxxp://ca.archive.ubuntu.com/ubuntu/]Index of /ubuntu] lucid-updates main restricted
12.
13.## N.B. software from this repository is ENTIRELY UNSUPPORTED by the Ubuntu
14.## team. Also, please note that software in universe WILL NOT receive any
15.## review or updates from the Ubuntu security team.
16.deb hxxp://ca.archive.ubuntu.com/ubuntu/]Index of /ubuntu] lucid universe
17.deb-src hxxp://ca.archive.ubuntu.com/ubuntu/]Index of /ubuntu] lucid universe
18.deb hxxp://ca.archive.ubuntu.com/ubuntu/]Index of /ubuntu] lucid-updates universe
19.deb-src hxxp://ca.archive.ubuntu.com/ubuntu/]Index of /ubuntu] lucid-updates universe
20.
21.## N.B. software from this repository is ENTIRELY UNSUPPORTED by the Ubuntu
22.## team, and may not be under a free licence. Please satisfy yourself as to
23.## your rights to use the software. Also, please note that software in
24.## multiverse WILL NOT receive any review or updates from the Ubuntu
25.## security team.
26.deb hxxp://ca.archive.ubuntu.com/ubuntu/]Index of /ubuntu] lucid multiverse
27.deb-src hxxp://ca.archive.ubuntu.com/ubuntu/]Index of /ubuntu] lucid multiverse
28.deb hxxp://ca.archive.ubuntu.com/ubuntu/]Index of /ubuntu] lucid-updates multiverse
29.deb-src hxxp://ca.archive.ubuntu.com/ubuntu/]Index of /ubuntu] lucid-updates multiverse
30.
31.## Uncomment the following two lines to add software from the 'backports'
32.## repository.
33.## N.B. software from this repository may not have been tested as
34.## extensively as that contained in the main release, although it includes
35.## newer versions of some applications which may provide useful features.
36.## Also, please note that software in backports WILL NOT receive any review
37.## or updates from the Ubuntu security team.
38.# deb hxxp://ca.archive.ubuntu.com/ubuntu/]Index of /ubuntu] lucid-backports main restricted universe multiverse
39.# deb-src hxxp://ca.archive.ubuntu.com/ubuntu/]Index of /ubuntu] lucid-backports main restricted universe multiverse
40.
41.## Uncomment the following two lines to add software from Canonical's
42.## 'partner' repository.
43.## This software is not part of Ubuntu, but is offered by Canonical and the
44.## respective vendors as a service to Ubuntu users.
45.# deb hxxp://archive.canonical.com/ubuntu]Index of /ubuntu] lucid partner
46.# deb-src hxxp://archive.canonical.com/ubuntu]Index of /ubuntu] lucid partner
47.
48.deb hxxp://security.ubuntu.com/ubuntu]Index of /ubuntu] lucid-security main restricted
49.deb-src hxxp://security.ubuntu.com/ubuntu]Index of /ubuntu] lucid-security main restricted
50.deb hxxp://security.ubuntu.com/ubuntu]Index of /ubuntu] lucid-security universe
51.deb-src hxxp://security.ubuntu.com/ubuntu]Index of /ubuntu] lucid-security universe
52.deb hxxp://security.ubuntu.com/ubuntu]Index of /ubuntu] lucid-security multiverse
53.deb-src hxxp://security.ubuntu.com/ubuntu]Index of /ubuntu] lucid-security multiverse
54.deb hxxp://ppa.launchpad.net/cairo-dock-team/ppa/ubuntu]Index of /cairo-dock-team/ppa/ubuntu] lucid main ##
55.# Cairo-Dock-PPA-Stable