Compiz 0.5 arrived in unstable a while ago. I usually run testing, but the Compiz 0.3.6 I used came from experimental. Unfortunately, an installation of Compiz 0.5 from unstable on a testing system would update libc6 and hence almost all of the system to unstable. I waited.
Initially, Compiz started, but all windows were empty, blank, void. The windows were there, I could click on links in a browser window, but I could see nothing but a blank window. Pop-up menus didn’t even display, though they too were there, but invisible.
After much experimenting and searching and reading fora and blogs (using a Metacity session), I discovered that I needed to update the the latest version of xserver-xorg-core from unstable. That solved the blank window problem.
Now I could see the content of my windows. It is actually quite nice, once you’ve tried the opposite
The windows had no decorations, however. No titlebar, no borders, but naked and ashamed.
This was a bit harder to solve, but in the end I discovered that the package “libdecoration0” had version 0.3.6, so it had not been upgraded for some reason, probably due to an unversioned depends rule in the Compiz packages.
A manual upgrade of libdecoration0 solved the problem, and now Compiz 0.5 works very well on my little laptop.