Comment 4 for bug 721125

After spending some time seeing when this is 'successful' vs. not (3 distinct methods 'work' with all autohide modes), it seems issue. if any, is the dimming of the launcher icons. The launcher is only active when the icons are at their brightest, ie. hitting the right spot and not unsetting on exiting into the launcher.
So the changes described will likely make this easier to do, and recognize the action in the first place.

Though reading thru the usability report from Nov., it wouldn't surprise me if many users are confused by the dual purpose of that area, things that are hidden are just that to many. There is nothing visible to suggest using the left side of the box vs. the icon in the middle which produces a dimmed launcher.