All of a sudden my track pad doesn't work properly and mouse pointer is jumping all over my screen

Question

Help, it feels like someone else is controlling my mouse.  This just started happening.  My trackpad doesn't work or works sporadically.  While typing the pointer is scrolling all over my screen.  This is really annoying.

Answer 1

Great tip! Your suggestion to check for a swollen battery in my laptop is working for me. You should get credit for solving the problem.
On my MacBook Pro (2008), my cursor was out-of-control for the past couple of days, like it was having a sissy-fit. In TextEdit, for example, I would enter text, but the text would no longer be entered smoothly, in sync with my typing. Nor would the text appear where I wanted it go. Sometimes, the text I was typing, say in the last line of the document, would jump and insert itself somewhere above in the document. Sometimes, entire lines of text, or entire paragraphs, would get highlighted and then immediately deleted upon my hitting the next keystroke. Not an acceptable way to work!
I tested this odd behavior in Leopard and in Snow Leopard and in Lion, which are all partitioned on my laptop's hard drive. Since I could not isolate the problem to any one version of the Mac OS, I began to fear that my motherboard had gotten compromised and went defective on me.
Your tip proved that it was merely a swollen battery that was the cause of my problems. I was able to confirm this by removing the original battery (now 4 years old) and placing it on a hard surface. It rocked like a see-saw, ever so slightly, about 1/8-inch to 1/4-inch at the far sides of the rocking motion. When I looked at that original, swollen battery from the side, I got further indication that your insight was likely correct, for I could spy the area where the swelling was occurring: it was at an edge in the middle of the battery, and it was separating from the base by about 1/16-inch, just enough to make me wonder why the "springiness" had suddenly disappeared from the central portion of my trackpad.
That change in the touch and the lack of aural feedback (i.e. no "click" sound or feeling) when I depressed the trackpad in the central section, was my first clue that something was wrong. The crazy cursor behavior on-screen was further indication that something was amiss.
I type this reply under A/C power, as the replacement battery, which I had purchased from Other World Computing back in September 2011 for just such an eventuality, is now charging. At first, I was worried that the replacement battery was a dud, for it was stuck on 0% for nearly 10-15 minutes before it began to take a charge. But, 30 minutes of paience has paid off: the replacement battery is now at 15% and getting more powerful by the minute.
bowlerboy