Comment 18 for bug 363375

To clarify Leon's method a little, the terminal with the Xorg.0.log trace needs to be on the *secondary* screen, and your enter key needs to be held down while focused on it. In my case, this will trigger the bug 90% of the time, and I get those "invalid input device" messages in 40-50 line blocks.

However, if I put the terminal on primary screen, the mouse doesn't get stuck. I still get those "invalid input device" messages, but they are far less frequent in this case.