I’ve found these infos on the net:
- http://forums.macnn.com/90/mac-os-x/353015/jerky-trackpad-on-mbp-with-leopard/
- http://discussions.apple.com/thread.jspa?messageID=6715850
- http://discussions.apple.com/thread.jspa?messageID=6229260
Indeed, the mouse cursor somehow jumps under certain circumstances. Here it happens after waking up from sleep mode even though I have 10.5.2 installed. After turning off WLAN the mouse cursor seems totally uncontrollble by trackpad, but plugging in a mouse always helps. Also the system load is increased and all graphical tasks like moving windows, switching spaces and going into exposé is jerking as well. On iStat pro I can see user load up to 30% when moving the mouse fast.
When regarding the system usage by ‘top -o cpu’ and heavily moving the mouse, the foreground task uses much cpu time. Another process always uses much cpu time: ‘WindowServer’. I’ve tried to ‘kill -HUP $pid’, and it restarted the window server like you can guess. But the mouse cursor still remains jerky when using the trackpad.
At the moment there is really no workaround and no solution to stop that except a reboot.