Middle-clicking on the titlebar lowers it, but doesn't change focus: the bottom window keeps focus. In <http://bugzilla.gnome.org/show_bug.cgi?id=135786> we discussed and changed this in Metacity. Basically, in click-to-focus mode, we don't want to break the "focused window is on top" invariant. See the discussion on Gnome bug #135786 for the long version. I tried this with the current release version of Ubuntu, which I guess is Ubuntu 8.04 / Xorg 7.3. I'm not running it right now, so I can't check easily. I read somewhere that Compiz was basically trying to have the same behavior as Metacity. I don't know if that's an actual concern, but the Compiz behavior is both different from Metacity, and internally inconsistent.
Mass closure: This bug has been untouched for more than six years, and is not obviously still valid. Please reopen this bug or file a new report if you continue to experience issues with current releases.
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