Hmmm. The more I used my MacBook Pro (the new one, w/a 15″ Retina display), the more little glitches I discover. The latest is that the trackpad will just go crazy every once in awhile, making it nearly impossible to control the cursor.
I first noticed this last night when the cursor seemed to develop a mind of its own and I could barely control it. The problem seemed even worse on the right side than on the left side, but it was bad just the same.
Unsure of what was happening, I chalked it up to (maybe?) having dripped a bit of condensation from my drink onto the trackpad. It seemed dry, but perhaps a little moisture got into the crack(s) around the edge resulting in erratic behavior.
I decided to put it to sleep for the night and go to bed. When I awoke this morning, it was back to its old self. Problem solved? Not quite.
After using it off and on for a couple of hours, my trackpad once again went haywire. In this case, it was even worse then before with the cursor repeatedly “bouncing” off the bottom of the screen even though I wasn’t touching the trackpad.
I responded by closing the case and then re-waking the computer. That solved it and it’s been okay in the half hour or so since. Very strange.
Like the difficulties recognizing USB devices via the Thunderbolt display, this problem has been well-documented in various discussion forums. Unfortunately, there are no clear causes or solutions.
Troubleshooting intermittent problems like this can be very difficult. One possibility is to press down firmly on the upper corners of the trackpad. Apparently this can help to re-seat the trackpad and restore normal performance.