Perhaps it's related to this gtk+ bug: https://bugzilla.gnome.org/show_bug.cgi?id=640995
Especially the second video shows a issue very similar to this. ** Bug watch added: GNOME Bug Tracker #640995 https://bugzilla.gnome.org/show_bug.cgi?id=640995 -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/961518 Title: Menu rendering leaves lingering shadow outlines To manage notifications about this bug go to: https://bugs.launchpad.net/compiz/+bug/961518/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
