Still occurs today. xorg log attached. FYI, clicking left and right buttons at the same time works, so perhaps a bug in xserver-xorg-input-mouse?
** Attachment added: "Xorg.0.log" http://librarian.launchpad.net/6567966/Xorg.0.log -- [Feisty] Middle click fails with no action https://launchpad.net/bugs/83571 -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs