Comment 4 for bug 943194

We have code for handling Alt keydown in firefox and thunderbird here: http://bazaar.launchpad.net/~extension-hackers/globalmenu-extension/trunk/view/head:/extensions/globalmenu/components/src/uGlobalMenuBar.cpp#L494, but we don't see these events when running in Unity now.

Disabling the shortcut for the HUD fixes it