My late 2008 13" MacBook (Snow Leopard) has become so erratic that it is almost impossible to use. (Using another MacBook now).
Hard to believe it is not an OS or update issue since it appears to be very pervasive. Anyone heard from Apple??
Any fix other than 3-prong plugs and dusty corners? (Wipe the trackpad many time and the apple power cord is already 3-prong).
Some users have reported issues with battery expansion causing problems with their trackpads. Try removing the battery and testing the MacBook while using just the power cord. If this works, replace the battery.
Best of luck.
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