Comment 62 for bug 68370

Corrected version to #2 from my previous post:

2) I have a weird behaviour that hasn't been mentioned above: So long as two users are running (even after fixing it by Ctrl-Alt-F7 and Ctrl-Alt-F9), using the trackball will also simultaneously move the mouse up and down. (So you have to move it back up after you've scrolled down a screen, or you'll fall out of the correct frame.) Once the other user logs out, however, then the offending user's mouse is back to normal. (Also, the mouse seems to move too fast while this is happening; others have mentioned this as an occasional behaviour.) This has only happened to me a couple of times, and I can't reproduce it consistently.