Error with playonlinux

open terminal and run "gksudo gedit /etc/apt/sources.list" giving your password when instructed.
Then examine the file before you.
IT should appear like this

# comments go here
source lines go here usually pointing to something around ubuntu.com

Anything not preceeded by a # or pointing at ubuntu.com should be removed.
This will most undeniably fix the problem with package manager.
As for playonlinux, I don't even know what that is.

Hi there
had a look through, but didn't see anything. Anyway, here is what the sources list 'said':

# deb cdrom:[Ubuntu 8.10 _Intrepid Ibex_ - Release i386 (20081029.5)]/ intrepid main restricted
# See http://help.ubuntu.com/community/UpgradeNotes for how to upgrade to
# newer versions of the distribution.

deb cdrom:[Edubuntu 8.10 _Intrepid Ibex_ - Release i386 Binary-1 (20081027.1)]/ intrepid main restricted
deb http://nz.archive.ubuntu.com/ubuntu/ intrepid main restricted
deb-src http://nz.archive.ubuntu.com/ubuntu/ intrepid main restricted

## Major bug fix updates produced after the final release of the
## distribution.
deb http://nz.archive.ubuntu.com/ubuntu/ intrepid-updates main restricted
deb-src http://nz.archive.ubuntu.com/ubuntu/ intrepid-updates main restricted

## 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.
deb http://nz.archive.ubuntu.com/ubuntu/ intrepid universe
deb-src http://nz.archive.ubuntu.com/ubuntu/ intrepid universe
deb http://nz.archive.ubuntu.com/ubuntu/ intrepid-updates universe
deb-src http://nz.archive.ubuntu.com/ubuntu/ intrepid-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.
deb http://nz.archive.ubuntu.com/ubuntu/ intrepid multiverse
deb-src http://nz.archive.ubuntu.com/ubuntu/ intrepid multiverse
deb http://nz.archive.ubuntu.com/ubuntu/ intrepid-updates multiverse
deb-src http://nz.archive.ubuntu.com/ubuntu/ intrepid-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-src http://nz.archive.ubuntu.com/ubuntu/ intrepid-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 intrepid partner
# deb-src http://archive.canonical.com/ubuntu intrepid partner

deb http://security.ubuntu.com/ubuntu intrepid-security main restricted
deb-src http://security.ubuntu.com/ubuntu intrepid-security main restricted
deb http://security.ubuntu.com/ubuntu intrepid-security universe
deb-src http://security.ubuntu.com/ubuntu intrepid-security universe
deb http://security.ubuntu.com/ubuntu intrepid-security multiverse
deb-src http://security.ubuntu.com/ubuntu intrepid-security multiverse

deb http://nz.archive.ubuntu.com/ubuntu/ intrepid-proposed restricted main multiverse universe
deb http://nz.archive.ubuntu.com/ubuntu/ intrepid-backports restricted main multiverse universe

Hi there
somehow it's been deleted and there are no more error messages. I can now install updates.
Seasons greetings