Q: I just did the latest iMac software upgrade 2 days ago and now my trackpad is completely erratic. It opens files, deletes emails, etc, all on it's own.

Crazy doesn't really tell us anything, can you be more descriptive?

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. Reset the System Management Controller.

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

4. 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.

5. 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.

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

7. 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.

I am also experiencing this after the most recent update which is the only new variable. iMac with a trackpad. It's looking like software to me

Chris Doyle wrote:

 

I am also experiencing this after the most recent update which is the only new variable. iMac with a trackpad. It's looking like software to me

Rather than posting a me too why not follow some of the suggestions provided by Linc Davis??

The erratic jumping - external trackpad and magic mouse started for me after I updated to 10.8.4.

I reinstalled Lion online (2.5 hrs) and it returned me to 10.8.3.  So far the bluetooth jumping issues have not reoccurred. External trackpad and magic mouse both stable. I am waiting to see if this changes.

I'm inclined to think it's not a hardware issue, but connected to the 10.8.4 update.

If this issue is as frustrating as it was for me give it a try.

Good luck, Steven

To reinstall Lion online.

http://www.apple.com/uk/osx/recovery/

Press Command + R then chose the re-install Lion option.

Borne2357 wrote:

 

The erratic jumping - external trackpad and magic mouse started for me after I updated to 10.8.4.

 

I reinstalled Lion online (2.5 hrs) and it returned me to 10.8.3.  So far the bluetooth jumping issues have not reoccurred. External trackpad and magic mouse both stable. I am waiting to see if this changes.

 

I'm inclined to think it's not a hardware issue, but connected to the 10.8.4 update.

 

If this issue is as frustrating as it was for me give it a try.

 

Good luck, Steven

 

To reinstall Lion online.

 

http://www.apple.com/uk/osx/recovery/

 

Press Command + R then chose the re-install Lion option.

10.8.4 is incredibly stable and is not the cause of your problems. However they could be caused by a corrupt download or corrupt install. What you should have done is re-installed 10.8.4 and if the issue still was there then re-downloaded 10.8.4 Update Combo and re-installed it.

Okay Rick, will give it a go and re-download 10.8.4 update combo. But there was no indication that my first download was corrupted in anyway.

I'd be interested in knowing if the 10.8.4 combo solved this problem as it sound exactly like my own problems with the Magic Trackpad since updating.

Thanks.

Well - to tell the truth - not really. There was a slight improvement I suppose. What I have ended up doing is disconnecting the external magic trackpad.

I have a MacBook Pro and I was using the external magic trackpad along with a blue tooth Magic Mouse and bluetooth external keyboard. With all three connected the cursor was doing all kind of weird things without my permission. But since I have disconnected the external magic trackpad all seems to be very stable.

I have a hunch that part of the problem is you can't isolate the magic trackpad from the trackpad on the MacBook Pro. They both operate at the same time even when the external one is connected. Perhaps they are interfering with each other, but I can't test this as I cannot find a way to turn the internal one off.

It could be something to do with the magic track pad, but I'm not going to buy another just to find out. It was working fine until the update and others who have had trouble tried that option and it didn't make a difference.

I will wait awhile for another update of the system and then try my magic trackpad again. Heigh Ho!

Sorry I can't be of more help.

Thanks. I feel like this problem appeared after the last update. I switched to my Magic Mouse and all seemed well for awhile, but now it's acting up. I have an iMac, so it's not interference from another input device. Even went through to house and turned off Bluetooth in all my other idevices and my MacBook Air. No change.

I have this exact same problem. Started yesterday. on 10.8.4 iMac.

Track pad going of and clicking and opening apps, files you name it..

Pulled out my Magic mouse and working with no issues. The only thing I have noticed is I have a ne install of Hype 2. Which was the first thing I was using when  it started. Today I connected the Track pad. All ok until I opened up Hype 2. Coisidence possibly.

Notice also in console a lot of  WindowServer[129]: CGXSetWindowBackgroundBlurRadius: Invalid window 0xffffffff.