Q: Erratic touchpad

Try the tips suggested in this article from Apple.

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

Reset PRAM.  http://support.apple.com/kb/PH4405

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

Choose the method for:

"Resetting SMC on portables with a battery you should not remove on your own".

If this does not help, contact Apple.

Best.

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.

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 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 tested.

Did you follow the instructions in the Apple Support article?

Hello, thanks for starting this topic and thanks to dominic and Linc for helping out. I am having a similar problem to E-Rager. There are some wrinkles to my case, however, so I was hoping to get some advice if that wouldn't be an imposition. FYI my MacBook Pro is from late 2009 and is running Snow Leopard (behind the times, I know!). I had the hard drive and battery replaced in late 2012 and early 2013, respectively.

The main wrinkle is that I accidentally splashed a bit of water on my track pad the other day. Could some water have seeped into its innards and be causing erratic behavior similar to E-Rager's? I'm experiencing the same thing -- erratic movement, phantom clicks, control-clicking instead of regular clicking, etc.

Just in case the water coincided with some deeper issue, I've followed the recs provided here:

-verified I'm doing what the support article says

-rebooted in safe mode with the same trackpad behavior

-reset PRAM and SMC

-verified that no other devices are being detected as connected to my computer

-Bluetooth is off

-turned off network access to verify no one is remotely controlling my computer

-can't detect any problems with the battery, and the erratic mouse behavior continues whether I'm using battery or plug power

Another oddity: when I attach my USB mouse the problem goes away. No erratic movement and no clicking problems. Could this indicate that the problem is a physical/hardware issue (such as water!) with the trackpad itself and not some system/software problem?

So now I'm wondering what's next. Could there be a problem I'm not thinking of? Is the water the likely culprit, and if so should that clear up on its own? Can I do anything about it?

Many thanks!!!

OK, I spoke too soon on one thing -- after using my USB mouse for 10 minutes or so, I got my first phantom clicks and erratic movements. I still works way better than the trackpad; it seems like the movements of the USB mouse are being "interrupted" by the trackpad instead of simply being erratic in themselves.

I want to report I had the same kind of problem.  Removed the battery and presto it works properly.

PROBLEM SOLVED!

Thank the Lord! My mouse cursor was moving erratically, seemed to be opening tabs, maybe doing the equivalent of holding shift and dragging, minimized windows, etc. Pretty much the same problems I see on other's posts.

I tried dissonnecting WI-FI, then shutting off Bluetooth, Disconnected and Turned off my Bluetooth Mouse, disconnected my wireless keyboard nub from the USB port, tried shutting off my Macbook and restrarting. I even shut the lid of my Macbook and worked off my second monitor in clamshell mode. NOTHING WORKED.

I thought I was hacked or had some type of Malware for sure, but it was a simple fix that I found on another help board.

I clean my Mac, keyboard and mouse regularly and had just got done wiping everything with a cloth with a mixture of warm water and rubbing alcohol (recommended)

I saw on another board that someone fixed their problem by moving their trackpad (gently) to the right, since the trackpad seemed to be too snug on the left side of the macbook body edge it sits in.

I moved the trackpad over and it took care of my problem immediately.

It was comforting to learn that Malware on a Mac is in fact still rare and that it is unlikely that someone would hack into your computer to 'remote control' your machine and be obvious about it.

No ghost in the machine. Trackpad is incredibly sensiitive I've learned.

Share the knowledge!

Blessings!