I'm a complete Linux newbie. I've just upgraded from 10.04 to 12.04 LTS and all sorts of things have started to go wrong. One main problem is the fact that I can't add repos.

Example:

sudo add-apt-repository ppa:team-xbmc

outputs:

Traceback (most recent call last):   File "/usr/bin/add-apt-repository", line 8, in <module>
    from softwareproperties.SoftwareProperties import SoftwareProperties   File "/usr/lib/python2.7/dist-packages/softwareproperties/SoftwareProperties.py", line 53, in <module>
    from ppa import AddPPASigningKeyThread, expand_ppa_line   File "/usr/lib/python2.7/dist-packages/softwareproperties/ppa.py", line 27, in <module>
    import pycurl ImportError: librtmp.so.0: cannot open shared object file: No such file or directory

/etc/apt/sources.list

# deb cdrom:[Ubuntu 10.04.1 LTS _Lucid Lynx_ - Release i386 (20100816.1)]/ lucid main restricted
# deb cdrom:[Ubuntu 10.04.1 LTS _Lucid Lynx_ - Release i386 (20100816.1)]/ maverick main restricted
# See http://help.ubuntu.com/community/UpgradeNotes for how to upgrade to
# newer versions of the distribution.

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

## Major bug fix updates produced after the final release of the
## distribution.
deb http://archive.ubuntu.com/ubuntu precise-updates main restricted
deb-src http://archive.ubuntu.com/ubuntu precise-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://archive.ubuntu.com/ubuntu precise universe
deb-src http://archive.ubuntu.com/ubuntu precise universe
deb http://archive.ubuntu.com/ubuntu precise-updates universe
deb-src http://archive.ubuntu.com/ubuntu precise-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://archive.ubuntu.com/ubuntu precise multiverse
deb-src http://archive.ubuntu.com/ubuntu precise multiverse
deb http://archive.ubuntu.com/ubuntu precise-updates multiverse
deb-src http://archive.ubuntu.com/ubuntu precise-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://pt.archive.ubuntu.com/ubuntu/ lucid-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 lucid partner
# deb-src http://archive.canonical.com/ubuntu lucid partner

deb http://archive.ubuntu.com/ubuntu precise-security main restricted
deb-src http://archive.ubuntu.com/ubuntu precise-security main restricted
deb http://archive.ubuntu.com/ubuntu precise-security universe
deb-src http://archive.ubuntu.com/ubuntu precise-security universe
deb http://archive.ubuntu.com/ubuntu precise-security multiverse
deb-src http://archive.ubuntu.com/ubuntu precise-security multiverse
# deb http://ppa.launchpad.net/stebbins/handbrake-snapshots/ubuntu precise main # disabled on upgrade to precise

I have no clue what do do next. Should I just scrap this installation and start from scratch or is this fixable? librtmp.so.0 also shows up in error logs I've started to get from XBMC (I'm not sure if this is relevant info).

Thanks in advance for any help you can give me!