cursor jumping all over

Just an update.. I have experienced the problem with my MagicMouse recently. I have also experienced it with my Jambox, a bluetooth speaker.

Unfortunately, it doesn't seem that the problem is isolated to USB or bluetooth in particular. I'm beginning to think it's a deeper hardware problem.

Has anyone else installed additional ram in their machines? I have, and I wonder if mismatched timings are the issue? Seems unlikely, but I'm exhausting all my options..

Cross post from https://discussions.apple.com/thread/3202337

Hi everyone.

At the suggestion of users above, I have resolved the jumpy mouse issue by unplugging my second monitor and rebooting. Obviously this is a work-around and not a solution, as I now have a blank monitor sitting next to me.

I still believe the issue is one related to mismanaged hardware resources in Lion, because:

1. It worked fine in Snow Leopard.
2. Dual-monitor support was terrible when Lion first launched, who is to say that they've resolved all the issues?
3. It affects devices that would use the internal system bus (USB, bluetooth, etc).

I am not intimately familiar with the hardware architecture of Apple machines, but here's my best guess of what's technically happening:

Secondary displays (connected via DVI) are running through the "southbridge" of certain machine builds, I believe. If this is the case, the southbridge bandwidth is likely becoming saturated when having to deal with a second monitor being connected. This makes sense as the "hang ups" we experience don't seem I/O or computationally related; I don't have my disk activity or network connections drop when I experience the problem.

Since we can now pin-point and work around the problem, what we need to do now is LET APPLE KNOW. I called support but they suggesting using the feedback form located at the link below.

Apple feedback link: http://www.apple.com/feedback/

If everyone on this thread submits feedback we'll have this issue resolved much faster!!!!

I have had the same problem, so i called apple support and they gave this link

http://support.apple.com/kb/HT1379?viewlocale=en_US

This solved the problem with my magic mouse jumping all over the place.

Hope it will help you as well.

/Andreas Carstensen

Probably a conflict between the Bluetooth signal and some other device operating in the 2.4 GHz frequency. I had this problem with my Magic Mouse and AirPort Extreme Base Station until I changed my AirPort to operate in the 5 GHz range.

FYI, the iPhone only supports connecting to a 2.4 GHz Wi-Fi signal.

I have a razer mouse that i recently purchased, and the cause of the jumping around crusor was my trackpad. My trackpad was not in a very nice condition when I bought the computer at the apple store, so I bought a mouse. But even with the mouse would start jumping. I stopped using the mouse and went back to the trackpad, but there was no difference. So I looked up on the internet, and I found out that there is a setting in the System Preferences where you can disable the built-in trackpad while the mouse is connected. I enabled it, and POOF! It was fixed 😀 hope this works for you.