I confirm that the two lines given in the script from beryl-project's wiki correct this issue. It seems finally that it came from incomplete howto and not from a bug in Xgl.
I just noticed that the French wiki was already modified to include those lines, but it seems absent from in wiki.ubuntu.com. Thanks a lot to Johan Brannlund for finding this fix (workaround ?) -- Incomplete logout options with XGL https://launchpad.net/bugs/36321 -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
