Originally Posted by six_storm
Here ya go:
The following packages are BROKEN:
compiz-core compiz-fusion-plugins-main compiz-gnome compiz-plugins
libcompizconfig0 libdecoration0 python-compizconfig
The following NEW packages will be automatically installed:
compizconfig-settings-manager freeglut3 libxcomposite1 mesa-utils
The following NEW packages will be installed:
compiz compizconfig-settings-manager freeglut3 libxcomposite1 mesa-utils
0 packages upgraded, 12 newly installed, 0 to remove and 0 not upgraded.
Need to get 2115kB of archives. After unpacking 8446kB will be used.
The following packages have unmet dependencies:
libcompizconfig0: Depends: libc6 (>= 2.6-1) but 2.3.6.ds1-13etch2 is installed .
Score is -19989
Alright there is your problem right there you need libc6 from either testing or unstable in order to be able to install it whereas you are running a stable system. So you have either the testing or unstable in your sources.list this is not really the way to go as it just won't work because too many things depend on libc6 it is the entire basis that the OS is built around/upon so when you upgrade it you may as well be running the higher branch it is in. What you could do is dist-upgrade to either testing or unstable, with testing being the best choice, then it should install and if needed you can do what is called apt pinning and get the odd package from unstable. Now whether you want to do this I don't know but if you want I can give you a hand getting the proper settings in place so it should work. Another option is just getting the Debian source for the package(s) then build them yourself and installing the resulting .deb files with dpkg if they don't have a hard dependency on on some package in testing/unstable (eg must have new feature in libc6 for instance) then they should be able to be built for your install then they will just work.
Another thing I see looking back here that you have the backports in you sources.list. So what does apt-cache policy libcompizconfig0
show you? If you see that it is at the backports site then you will want to remove/comment out the unstable line then update and try to install from there the work of building the packages for a stable install would have already been done so it should work fine.