I’ve been getting erratic behaviour on the Apple TrackPad since performing the upgrade to 10.7 on the MacPro (2006, 1,1).
Everything is fine and then as you move your finger across the surface, the on-screen cursor starts jumping about, sometimes in a predictable way (like its just missing event information from the trackpad), and other times like its getting the event information garbled as the cursor goes to completely unrelated parts of the screen.
It can do this shortly after a full restart of the system, or after long periods of running (days, including sleep/wake cycles).
I’ve found that turning off the TrackPad (hold down the trackpad power button until the light goes out, wait for the onscreen acknowledgement that its disconnected), and then power back on. That tends to sort it out.
I also have a Wacom Intuos tablet and mouse installed via USB, and they is unaffected when the TrackPad gets erratic, suggesting its a TrackPad/Bluetooth problem. There are no new Bluetooth devices.
Today I upgraded to 10.7.1 and the problem still exists. Sometimes it occurs multiple times per day, and sometimes goes days without occurring. I can’t see any correlation to other system activities.
TrackPad batteries are new and showing 90%+ in the Bluetooth menu.
**Update:** I’ve noticed that there are repeating bunch of USBMuxD messages in the console log, related to when the iPhone or iPad are connected. Looking for forum help on these suggested that these messages can result in erratic mouse behaviour, so maybe these problems are related.