The 3D desktop is not something that is really needed for daily work, but I wanted to try it. Unfortunately, I could not get the desktop effects to work the first time I tried. I enabled the livna repositories, installed the nVidia binary drivers and configured the X server to use them. However, telling the system to enable the Desktop Effects failed, and running glxinfo crashed with a "locking assertion failure" message.
Googling a bit, I found a page mentioning that one has to run the livna-config-display command to properly configure the X server. I think I did not do this, so I just ran this manually and later restarted X. No luck.
Fortunately, that same page also contained a snippet of the xorg.conf configuration file that was like this:
Section "Files"Effectively, my configuration file was lacking the path to the nVidia extensions subdirectory. Adding that line fixed the problem: now the server loads the correct GLX plugin, instead of the "generic" one that lives in the modules directory. I guess livna-config-display should have set that up automatically for me, but it didn't...
The desktop effects are now working :-) Now I figure out why compiz feels so slow... specially because I have the same problem at work with an Intel 965Q video card.