Although you've got different hardware, you're both running Xinerama to bind two graphics cards together, have similar backtraces, and the problem occurs when moving the pointer across a screen boundary. I'm marking this as a duplicate of bug #572113.
Although you've got different hardware, you're both running Xinerama to bind two graphics cards together, have similar backtraces, and the problem occurs when moving the pointer across a screen boundary. I'm marking this as a duplicate of bug #572113.