Dualhead unity panel shows up in the center when cursor is over the left corner

[Alessandro Bruni]

When having a dualhead configuration (twinview, nvidia drivers, but the same behavior has been found with nouveau) the unity panel shows up on the right screen, while the action that displays the panel is moving the cursor to the left edge of the screen. I think that this is incoherent and that it should be made possible to choose where to put the panel and how to trigger it's display/hide behavior.