Weird window-manager behavior when running stacked monitors

I'm running a pair of stacked monitors, with a larger (2048x1152) display above, and a smaller (1366x768 laptop panel) below. The laptop panel is set as the primary display.

When placing windows on the top (larger) monitor, window-placement is restricted. I can only place the window in certain regions of the screen. I haven't completely figured out the rules, but it seems as if the window-placement restrictions are dictated by the position of the lower monitor relative to the top monitor in the Display Settings. If I place the lower display in the "center" of the upper monitor, I can place windows on either side of the upper display. I can, however, resize the windows so that they cover most of the screen.

Also, when I open a new window, it's often placed into a narrow vertical strip at the side of one of the display.

My guess is that the window manager used by Gnome 3.2 isn't taking in to account the vertical configuration of the displays incorrectly when it's trying to figure out how where it can and can't place windows.

I'll be happy to provide more detailed information on request, but someone has GOT to have reported this bug before...!

ProblemType: Bug
DistroRelease: Ubuntu 11.10
Package: gnome-shell 3.2.1-0ubuntu1.1
ProcVersionSignature: Ubuntu 3.0.0-15.25-generic 3.0.13
Uname: Linux 3.0.0-15-generic x86_64
ApportVersion: 1.23-0ubuntu4
Architecture: amd64
Date: Wed Jan 18 09:28:42 2012
SourcePackage: gnome-shell
UpgradeStatus: No upgrade log present (probably fresh install)