For correct windows handle by gnome-shell like it's discussed in https://bugzilla.gnome.org/show_bug.cgi?id=643396 in which it's said That it was fixed upstream mid-2009 http://hg.mozilla.org/mozilla-central/rev/9ab3645be5aa
Will include with next revision bump.
Just landed upstream. Code freeze for .16 is this thursday, there will not be a bump made until it is released. Closing as it has been addressed on 1.9.2 branch and will filter down this upcoming release.