warning -- it's been a long time since i used debian
edit: i just went and looked at the libranet sources.list for 2.8
http://libranet.com/support/2.8/sources.list
and it's all sarge testing already so i would adjust the instructions bellow to "unstable" or "Sid" if that's where you want to go with it
i don't know how to get you out of the mess back to where you were but this might help you move forward if you are trying to shift to (unstable)
as dist-upgrade would imply
http://www.linuxmafia.com/faq/Debian...to-debian.html
the important point is to change you sources.list to (unstable) and put a # before everything that is not (unstable) then do update before trying to move on
you may want to just rename /etc/apt/preferences if there is one as well unless you understand pinning
important to note here that i am suggesting to move totally to debian unstable (Sid)
and not trying to keep a mixed system or trying to use the libranet "safe"
mixed sytems are possible but an advanced way to do debian
also keep an eye on debian so when "Sid" i think it is becomes testing i would switch back sources to (testing)for a while as they get things sorted out