dual display issue with gnome-3, a funny bug?

[mathfeel]

I connect my laptop to an external display. Since the max resolution, 1280x800 for the laptop and 1280x1024 for the external, have the same x-dimension, I stack them UP-DOWN style to get a 1280x1824 screen. Gnome-shell is at the bottom screen (laptop). Now if I try to put a window to the top screen, i can drag it only about halfway up then it would go no further! See this screenshot:

http://i4.photobucket.com/albums/y103/mathfield/gnome-3_pull-up.png

the Emacs window is stuck in the middle! This seems like a hilarious fail.

While on the topic, another interesting thing is if I setup the two display to be LEFT-RIGHT, with Gnome-shell in the laptop display on the left. I can move a window freely to the right side. But if I switch workspace, the window on the right side stays no matter which workspace I am in!! I am not sure if this is intended effect, but I kind of like it since I can keep a browser on the right screen and switch between workspaces, say between two coding sessions while keeping a programming reference constantly open in the browser. By the way, this behavior is also true for the previous UP-DOWN style, except now since the upper window is always divided into two, it gets confusing when one switches workspaces....

How's other's experience with gnome-3 multi-display?

EDIT: Just realized that there is a gconf2 key in