My system:
AMD Sempron 64
Asus M2NPV-MX
Install media: Kubuntu Feisty Fawn 7.04 Desktop AMD64 (final)
Modification made only through Adept such as:
uninstalled Kexi
installed ubuntu-restricted-etras, nvidia-glx, firefox, thunderbird, etc. (but nothing like easyubuntu)

I can't exactly remember what happened during the first times (something like this anyway, but additionally I also might have gotten a KNotify message), but when I try to add a mp3 ("Playlist"->"Add media") then amarok hangs after the "No MP3 Support" dialog comes up.


apt-cache policy amarok
amarok:
  Installed: 2:1.4.5-0ubuntu7
  Candidate: 2:1.4.5-0ubuntu7
  Version table:
 *** 2:1.4.5-0ubuntu7 0
        500 http://se.archive.ubuntu.com feisty/main Packages
        100 /var/lib/dpkg/status


cat /etc/apt/sources.list
# See http://help.ubuntu.com/community/UpgradeNotes for how to upgrade to
# newer versions of the distribution.

deb http://se.archive.ubuntu.com/ubuntu/ feisty main restricted
deb-src http://se.archive.ubuntu.com/ubuntu/ feisty main restricted

## 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, 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.
deb http://se.archive.ubuntu.com/ubuntu/ feisty universe
deb-src http://se.archive.ubuntu.com/ubuntu/ feisty 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://se.archive.ubuntu.com/ubuntu/ feisty multiverse
deb-src http://se.archive.ubuntu.com/ubuntu/ feisty 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://se.archive.ubuntu.com/ubuntu/ feisty-backports main restricted universe multiverse
# deb-src http://se.archive.ubuntu.com/ubuntu/ feisty-backports main restricted universe multiverse

deb http://security.ubuntu.com/ubuntu feisty-security main restricted
deb-src http://security.ubuntu.com/ubuntu feisty-security main restricted
deb http://security.ubuntu.com/ubuntu feisty-security universe
deb-src http://security.ubuntu.com/ubuntu feisty-security universe
deb http://security.ubuntu.com/ubuntu feisty-security multiverse
deb http://archive.ubuntu.com/ubuntu/ feisty-updates restricted main multiverse universe
deb-src http://security.ubuntu.com/ubuntu feisty-security multiverse