Comment 1 for bug 630193

I have the same problem. I'm on a stylistic tablet with wacom digitizer built-in. Stylus is the only input method, but clicking the unity launcher-icons does nothing (only nudges the icon).
Sometimes the very first icon I tap(click) launches the app, but subsequent clicks don't work on any icon.

right-clicking launcher icons work (shows menu)
right-clicking inside any maximised application window only does a quick show-hide of menu.
clicking a menu on the top global-menu-panel only does a show-hide. Like said above - appear on mousedown, disappear on mouseup.
Same "show-hide" effekt on the shutdown-button etc in top panel.

The menu and rightclick problem in applications seem to go away if Maximus is configured with no_maximise, and the menu is on a line of its own (not in top-panel).

I also discussed the problem here:
http://ubuntuforums.org/showthread.php?t=1595331