I have just fresh installed 12.04, there were a handful of packages that were upgraded right away (12 or so). Aside from that I haven't tweaked or installed anything else.
I have gone into my
System Settings ->
Behavior tab and turned on
Auto-hide the launcher.
At this point placing my mouse cursor to the far left edge of the screen should open my launcher. Here is a short video showing you what is happening.
I have tried setting the
Reveal Sensitivity all the way to low, and all the way to high and it still appears the same for me.
you will also notice in the video that there is a small dropshadow that appears on the edge of the screen when (imo) the sidebar should appear.
Is there a configuration I am missing? does Reveal Sensitivity not do what I would assume it does? Any help would be appreciated.