Q: Magic Trackpad Erratic Movement

Same here. When my Time Machine backup is going, the Magic Trackpad movement goes all wonky. After the backup stops, it gets better.

I'm using a Samsung USB 2.0 external drive for the Time Machine backup.

One thing I noticed that seem to help the issue a little bit when a backup is not going, is I replace a flourescent lightbulb in my desk map with an incandescent one. Apparently, the flourescent was interfering with the Magic Trackpad??

My trackpad is still not working well 100% of the time, but it has been a little improved. I even replaced it and still have the same problem so I know it's not the unit itself.

Part of the issue I think is a weak Bluetooth transceiver in the MacPro-lame. If I remove the MacPro cover, the issue seems better but I'm not going to operate with the cover off all the time.

Same here. I can't explain it very well because i do not speak english, but i suffer the same issue. Suddenly it stops to work and starts to do erratic movement.

I finally SOLVED this issue once and for all!

I bought a mini USB Bluetooth adapter and plugged it into the front of my MacPro, re-paired my trackpad and voila, problem fixed!

The USB adapater is made by Medialink but likely other brands would work and it was under $20.

Here's my video of it:

http://www.youtube.com/watch?v=QnnhGoXybmo

Fresh Batteries solved my problem.

Sorry, the video is here:

http://www.youtube.com/watch?v=oGRlcOq5kmQ

Interesting thread. I have had the same problem with erratic trackpad movement. I have a brand new MacBook Air 13" Late 2011 laptop. All was working 100% until I resurrected my Jawbone Bluetooth device which I used to use on my iPhone. I put the jawbone on charge, and in a short while the trackpad on my air went totally wild. Couldn't point to anything accurately, the cursor would jump all over the place. In short, the machine became unusable.

I called Apple support, they had me go through a few "resets" something like control-command-P and power button, to no avail. They finally gave me an appointment to go to an Apple Genius. So, I turned off the Air, and put it away. I also wrapped the jawbone in tin foil, and put it in a metal pot. When I did that the trackpad issue disappeared!

If I put the Jawbone on charge, the issue re-appears. This is with bluetooth turned off on the air.  Somehow, bluetooth from the jawbone is interefering with the internal trackpad on this air. I will not be going to the Genius tomorrow, but I will call Apple again and demonstrate the issue. This shouldn't be, as this trackpad is hard-wired and not a bluetooth device like all of you folks.

I've had a similar problem: pointer all over the place during Time Machine back up.  What I did was get the Time Machine further away from the iMac and Trackpad.  It does not seem to happen now.  You just need a long enough ethernet cable.  Obviously this isn't an option on a macbook.

I just bought a Magic Trackpad in 2012. Still the same problem.

This is the second MTP that I bought. I bought another one for work a week ago and tried it at home. For some reason that one had no issues. I was sold on how well it worked, so I purchased one for my personal use. My goal was to replace the trackpad on the Macbook Air itself, because using your hands close to each other has ergonomic issues. Immediately after installing and connecting the MTP with bluetooth, it started having erratic cursor problems. It's as if the cursor is programmed to accelerate on quick gestures. It behaves very differently from the trackpad on Macbook Air itself (which works perfectly).

Since reading this thread, I've moved away all cell phones from my desk. I've slowed down the speed setting of the trackpad. I've checked the batteries and they're at 100%. I have no wireless backup running. I've changed the wireless channel frequency on my Linksys router. All to no avail.

The problem feels like a performance bottleneck. Since neither of the CPUs, nor memory is pegged, I'm left to believe that it's a problem with the Bluetooth bandwidth or interference. (As I mentioned, the MTP is brand new, so extremely clean)

I'm very disappointed, as my goal was to decrease my ergonomic pain, but this is definitely increasing my pain.

I have the same problem: my MTP suddenly stopped working. The support person told me to replace it, which I did, but the problem persists. Apple doesn't seem to have a fix so I guess I'll just have to get a refund and stick with the mouse.

See here for a good workaround. I've had no problems since!

http://www.youtube.com/watch?v=QnnhGoXybmo

My MTP started playing up 3 days ago.  The only thing I've done is install the new messages beta app.  Changed batteries did not fix the issue. unpaired the devie and re-added it same issue.

Using a USB mouse works around the issue for me, would prefer that the MTP would work.

For me the problem was a flourescent light. I was at a coffee shop in a specific location when I first had the problem. Like a previous writer I called Apple Support and they walked me through a series of resets which seemed to "fix" the problem when I think the actual fix was plugging it in. Today (two weeks later with no problems) I returned to the same shop and sat in the same spot and had the same problem. When I plug the MBP into the outlet I have no problems. If I unplug it the problem returns. I unplugged it and unplugged the flourescent "open" sign sitting next to me and voila, works fine. I replicated, and tested the process a couple of times just to confirm and it is most certainly the flourescent light. Odd. Seems that Apple could easily fix this issue.

I resolved all my mouse and trackpad problems by moving my wireless router (in my case a Time Capsule) to the other side of my desk. It seems it's the wi-fi which causes interference.

I have same problem as well.. I noticed that MTP gets really drunk when Time Machine is backing up to Time Capsule.  Also sometime it wiggles when moving pointer if my iPhone (4S) is near.  I just wait till it finishes backing up..  and also move iPhone away from MTP's proximy.

MacBook Pro 13, BT Apple Keyboard, MTP.  24" monitor (ViewSonic).  Also Apple TV/Google Internet Box (which uses Bluetooth Remote) is like 4 feet from MTP.

Sigh.. been dealing with it for over a year...

Billy - I have absolutely no doubt it's a wi-fi conflict, and the fact that you're getting an acute problem when Time Machine is backing up seems to confirm that. I had exactly the same trouble. My TM is backing up right now, as I type, and I've got no problems becuase I moved my wifi device (router) away from the mouse and trackpad, which were both previously affected. I've had a trouble-free three weeks now. In my previous home office, I had no problems with the same hardware, so it's not a product defect as such, just a "bug".