Anyway, the point is that with the new system upgrade Beryl was uninstalled since it was marked as obsolete package. After some searching on the web I found that Beryl developers went over to Compiz. So the first step was to install the compiz manager. That was quite easy, just go to System -> Administration -> Synaptic Package Manager. Then search for "compizconfig-settings-manager".
After a successful installation the following menu entry should appear:
This is basically the compiz configuration window, where all the effects and stuff can be configured and activated. To use all this effects however, one has to open the "Appearance" dialog which is just the menu entry below.
If it works, everything is fine and Compiz effects will be used. In my case however the error message "The Composite extension is not available" appeared.
I found out that this is connected to my ATI proprietary drivers which I was using on Ubuntu. So I had to adjust some settings in order to make Compiz work.
sudo gedit /etc/X11/xorg.confIn the configuration file search for "extension" and you'll find something like this
Change the value "0" to "1" and save your settings. Then go back to the appearance preferences and try again to set the visual effects to "custom". If it works fine, otherwise you have to continue with step 2.
Option "Composite" "0"
Open a terminal (Press Alt+F2 and type "gnome-terminal"). Then type in "compiz --replace".
You should get something like this:
Then go on by typing (always in your terminal window):
Checking for Xgl: not present.
No whitelisted driver found
aborting and using fallback: /usr/bin/metacity
sudo apt-get install xserver-xgl
After installation, restart your X-server by pressing CRTL-ALT-BACKSPACE.
Compiz should work now.