Comment 18 for bug 357204

This problem is evidently still there in Lucid Lynx 10.04 LTS (i386 Desktop). I'm using an Itac Systems, Inc. Mouse-Trak trackball on th PS/2 mouse port, and as-shipped in the LiveCD, it takes multiple spins of the trackball to move the pointer from the left edge of the screen to the right edge. This trackball has its own built-in acceleration control that can be switched on and off with a button, and even with acceleration active it takes multiple spins to traverse the screen. When operating normally, a single spin of the ball is all it takes without acceleration; with acceleration a quick 20-40 degree rotation of the ball does it. (The Itac Mouse-Trak is an industrial trackball with a large, billiard-ball-sized phenolic ball mounted on precision plated steel shafts and ball bearings. When flicked with a fingertip, the ball will continue to spin for a second or so, unlike some cheap trackballs from Logitech, et al, using tiny, marble-sized plastic balls on simple friction bearings.)

When I move the mouse sensitivity control to "Low", it starts to behave more normally. When I move the sensitivity control to "High", the pointer becomes a slug.

Conclusion: The mouse sensitivity control sense is most definitely inverted. If it is running over a 0-255 range, as many 8-bit controls do, there may be an inadvertent subtraction or overflow occurring in the settings algorithm.

The mouse acceleration control sense appears to work correctly.