Comment 2 for bug 820553

I investigated the issue a bit, and according to my findings this is not a bug in unity-2d: if I remove the unity-2d related names from the "RequiredProviders" line in the /usr/share/gnome-session/sessions/ubuntu-2d.session file, the flickering still happens.

I suspect that this bug might be related to metacity: in fact, if I don't start metacity, no flickering occurs; and if I manually start metacity from an xterm (with no other window manager running), then flickering occurs inside the xterm.

I'm reassigning this to metacity for investigation.