Don't think updates work

I'd please like to add I run Ubuntu 10.04

Hi, please do this:
1. Open a terminal by hitting CTRL + ALT + T
2. Insert and run this command:
cat /etc/apt/sources.list -n

3. Copy and paste here all the output.

henning@henning-laptop:~$ cat/etc/apt/sources.list-n
bash: cat/etc/apt/sources.list-n: No such file or directory
henning@henning-laptop:~$ ^C
henning@henning-laptop:~$ cat /etc/apt/sources.list -n
     1 # deb cdrom:[Ubuntu 10.04.3 LTS _Lucid Lynx_ - Release i386 (20110720.1)]/ lucid main restricted
     2 # See http://help.ubuntu.com/community/UpgradeNotes for how to upgrade to
     3 # newer versions of the distribution.
     4
     5 deb http://www.nic.funet.fi/pub/mirrors/archive.ubuntu.com/ lucid main restricted
     6
     7 ## Major bug fix updates produced after the final release of the
     8 ## distribution.
     9 deb http://www.nic.funet.fi/pub/mirrors/archive.ubuntu.com/ lucid-updates main restricted
    10
    11 ## N.B. software from this repository is ENTIRELY UNSUPPORTED by the Ubuntu
    12 ## team. Also, please note that software in universe WILL NOT receive any
    13 ## review or updates from the Ubuntu security team.
    14 deb http://www.nic.funet.fi/pub/mirrors/archive.ubuntu.com/ lucid universe
    15 deb http://www.nic.funet.fi/pub/mirrors/archive.ubuntu.com/ lucid-updates universe
    16
    17 ## N.B. software from this repository is ENTIRELY UNSUPPORTED by the Ubuntu
    18 ## team, and may not be under a free licence. Please satisfy yourself as to
    19 ## your rights to use the software. Also, please note that software in
    20 ## multiverse WILL NOT receive any review or updates from the Ubuntu
    21 ## security team.
    22
    23 ## Uncomment the following two lines to add software from the 'backports'
    24 ## repository.
    25 ## N.B. software from this repository may not have been tested as
    26 ## extensively as that contained in the main release, although it includes
    27 ## newer versions of some applications which may provide useful features.
    28 ## Also, please note that software in backports WILL NOT receive any review
    29 ## or updates from the Ubuntu security team.
    30 # deb http://se.archive.ubuntu.com/ubuntu/ lucid-backports main restricted universe multiverse
    31 # deb-src http://se.archive.ubuntu.com/ubuntu/ lucid-backports main restricted universe multiverse
    32
    33 ## Uncomment the following two lines to add software from Canonical's
    34 ## 'partner' repository.
    35 ## This software is not part of Ubuntu, but is offered by Canonical and the
    36 ## respective vendors as a service to Ubuntu users.
    37 # deb http://archive.canonical.com/ubuntu lucid partner
    38 # deb-src http://archive.canonical.com/ubuntu lucid partner
    39
    40 deb http://www.nic.funet.fi/pub/mirrors/archive.ubuntu.com/ lucid-security main restricted
    41 deb http://www.nic.funet.fi/pub/mirrors/archive.ubuntu.com/ lucid-security universe
    42 deb http://archive.canonical.com./lucid partner
    43 deb http://archive.canonical.com/lucid partner
henning@henning-laptop:~$

thanks for helping me Enrico

Delete the 'dot' after com in line:
42 deb http://archive.canonical.com./lucid partner

Open sources.list:
gksudo gedit /etc/apt/sources.list

When finished save and close the file.
Run:
sudo apt-get update
sudo apt-get upgrade

Thanks Sam_(and-sam), I managed to get the 'dot' away. But when running: sudo apt-get update

I get: E Malformed line 42 in source list /etc/apt/sources.list (dist parse)

Now what?

regards

Thanks Sam_, that solved my question.