Q: the trackpad is behaving erratically

see

http://support.apple.com/kb/TS1449

and

Reset SMC

http://support.apple.com/kb/HT3964

could also be the battery swelling up

There are several possible causes for this issue. Take each of the following steps until it's resolved.

1. Follow the instructions in this support article.

2. Open the Bluetooth preference pane in System Preferences and check for unknown or forgotten input devices. Disconnect any USB input devices that you aren't using.

3. Boot in safe mode and test, preferably without launching any third-party applications. If you don't have the problem in safe mode, but it comes back when you reboot as usual, stop here and post your results. If you can't boot in safe mode, do the same. If you booted in safe mode and there was no change, go on to the next step.

4. Reset the System Management Controller.

5. If you're using a Bluetooth trackpad, investigate potential sources of interference, including USB 3 devices.

6. A swollen battery in a MacBook Pro or Air can impinge on the trackpad from below and cause erratic behavior. If you have trouble clicking the trackpad, this is likely the reason. The battery must be replaced without delay.

7. There's a report that a (possibly defective) Thunderbolt Ethernet adapter can cause the built-in trackpad of a MacBook to  behave erratically. If you're using such an adapter, disconnect it and test.

8. There's also a report of erratic cursor movements caused by an external display that was connected but not turned on.

9. If none of the above applies, or if you have another reason to think that your computer is being remotely controlled, remove it from the network by turning off Wi-Fi (or your Wi-Fi access point), disconnecting from a Bluetooth network link, and unplugging the Ethernet cable or USB modem, whichever is applicable. If the cursor movements stop at once, you should suspect an intrusion.

10. Make a "Genius" appointment at an Apple Store to have the machine and/or external trackpad tested.

Linc

I love my tracpad for the imac I guess it is a magic trackpad

yesterday it started not resoonding to movement

but it would respond to a click

once when I reboted it worked again

but not anymore

what do you think it is

and what can I do

is it a hardware (tackpad or mac) problem

or a software one

thanks

bart

and I just tried it on my laptop and the same thing happens

My MacBook Pro has had this problem off and on and I accidentally discovered a way to "cure" it. When the cursor starts getting erratic, I quickly close the cover of my MacBook and wait a little. When I open it again, the cursor has usually calmed down, at least for a minute. Sometimes I have to do this over and over for several days, and then it finally stops. This last time it happened, it stopped in much less time than it had before. It takes patience, but it works, and you don't need to call a technician.

jazzrascal:

This is excessively bad advice! What you are recommending really just amounts to ignoring the symptoms and hoping that the problem goes away. If this is being caused by a swollen battery, ignoring it could result in permanent damage to the computer. If it is actually being caused by someone accessing the computer remotely, ignoring it gives them more opportunities to do something malicious.

Please stop posting this advice everywhere!