Given a multi-headed X server in Zaphod mode (i.g. having 2 logical
screens :0.0 and :0,1), the mouse is getting stuck on the right most
screen.
This is a known (and fixed!) bug in Xorg:
http://bugs.freedesktop.org/show_bug.cgi?id=12145
However, it does NOT seem to have made it to Fedora, as my FC10 machine
is showing the very symptom.