Please describe the problem:
When moving maximized windows from one screen to another in a xinerama/twinview configuration, the window rapidly switches from screen1 to screen2 to screen1 to screen2 and so on while the window is being dragged.

Each mouse update toggles the screen on which the window appears.

Both screen resolutions are the same

Steps to reproduce:
1. Enable xinerama
2. Maximize window
3. Move window from one screen to another


Actual results:
Window rapidly alternates between the two both screens on each mouse movement.

Expected results:
The window should appear on the screen that the mouse is inside and stay there.

Does this happen every time?
Yes

Other information:
metacity-2.17.2-1.fc7
Fedora Core Devel (Rawhide)
Aiglx+Twinview
x86_64
both 1280x1024
No vertical panels. 
Two 24px horizontal panels on each screen (top and bottom)