gstreamer help

hi...

previously i was not able to play .avi,.dat or .mpeg in totem

then i done this

in /etc/apt/sources.list

deb http://archive.ubuntu.com/ubuntu breezy-backports main restricted universe multiverse
deb-src http://archive.ubuntu.com/ubuntu breezy-backports main restricted universe multiverse

deb http://ubuntu-backports.mirrormax.net breezy-extras main restricted universe multiverse

deb http://packages.freecontrib.org/ubuntu/plf breezy free non-free
deb-src http://packages.freecontrib.org/ubuntu/plf breezy free non-free

And in the terminal windows use the following instead :

sudo apt-get install gstreamer0.8-plugins
sudo apt-get install gstreamer0.8-lame
sudo apt-get install gstreamer0.8-ffmpeg
sudo apt-get install lame
sudo apt-get install sox
sudo apt-get install ffmpeg
sudo apt-get install mjpegtools
sudo apt-get install vorbis-tools
sudo apt-get install w32codecs
gst-register-0.8

i was not able to
install gstreamer0.8-lame
install lame
install sox
install vorbis-tools
install mjpegtools

rest everything installed correctly

then i was able to run .dat files in totem and get video and audio o/p , but not .avi or .mpeg files

The problem i now have is that the video is now gone
just im getting a blue screen but audio is there(while playing .dat files)

How can i get rid of this problem?
How can i play .dat files back with video?
Can any1 help?