This is on a 2010 version updated regularly so it should be the same as 2011. I did try aptupgrade but was told this had already been done.
I see. Then open a terminal (konsole), enter
give root password when prompted then enter
if you are not using LXDE, substitute the text editor for the DE you are using - kwrite, gedit, geany - or whatever editor you prefer. On the line of your selected repo, add 'unstable' at the end -
..... main updates nonfree kde4 games unstable
Save the change. Then in a terminal, as root (su)
apt-get update && apt-get install synaptic Important: Do not run apt-get dist-upgrade!
After installing synaptic, edit your sources list to remove unstable
. This is very important. If you fail to do this, you will end with a borked system.