Hi, so I can reliably reproduce the issues I mentioned in #15. I have a 1600 x 900 display build into my laptop, and a 1920 x 1080 display that I use at work. I have them arranged like so:
![screenshot from 2014-03-28 11 15 56](https://cloud.githubusercontent.com/assets/2838640/2551230/0b9a2666-b68c-11e3-821f-0af242007cd3.png)
Note that the second display is actually the primary ( with the panel, dock, and workspace dock ).
When I set the first (built-in) display to be the primary, everything's fine. When I set the second display to be the primary, that's when the troubles arise. The dock doesn't show in overview, intellihide doesn't work, and sometime dragging windows between workspaces doesn't work. Additionally, looking glass shows the same error from before I updated this extension:
![screenshot from 2014-03-28 11 26 41](https://cloud.githubusercontent.com/assets/2838640/2551344/83a6de8c-b68d-11e3-9c7d-2c0712b34407.png)
I also have a 1440 x 900 display that I use at home, but I don't remember what was working on it ( I just figured this out this morning ). When I get home tonight, I'll check.
One last thing. Isn't really your problem, but every time I disconnect and reconnect a monitor, I need to restart gnome shell to get the workspace preview thing to show. I guess I should really report that to gnome shell, aha.
Let me know how I can help :).