FWIW, I have almost _never_ seen this. The only time I ever get this is
if I am moving the mouse when I hit the console switch on my 4-port console
switch, but it corrects itself almost instantaneously.
I also do not see this and have not ever. I use the MouseMan+ logitech mouse
on psm0 (with the "wheel" for the middle button) and do not use moused since
that screws over getting "button 4" and "button 5" messages I need in X for