Comment 5 for bug 938758

I would like to add additional information about this bug in a different configuration:

I am using 12.04 (complete updates as of March 14, 2012), in a Virtual Box VM v 4.1.8 on Mac OS X 10.7.3

My Ubuntu guest is run in full screen mode on the external monitor. The external monitor is located to the right of the built in display. That means, the left edge of the Ubuntu guest is at the middle of the host total screen area.

built-in display | External monitor
built-in display | Ubuntu Full screen
built-in display | dock/launcher

When the dock is configured for auto hide, moving the mouse to the left edge of the VM, does not reveal the dock/launcher. Moving past will only result in mouse leaving the VM and entering the host desktop. Adjusting the reveal sensitivity doesnt seem to affect this behavior in anyway.

So auto-hide feature is unusable in this case.