Bluetooth Apple Magic Mouse jumps and moves erraticlly on screen

Same for me: Erratic and Jumping Magic Mouse (pointer of course) since a few days.
After reading comments, disconnected 2 firewire Disks (self-power-plugged), an additional Display, and Spider3 probe (iMac-powered). turned off wireless-track-pad. Power off iMac, 5 minutes, then On.

Everything wend back to normal.

Try to reconnect peripherals one by one. Trackpad Ok at the moment.

yep its a second monitor problem... i was wondering why my magic mouse acted out constantly since a while now and remembered that this wasnt the case when i got the imac.
so i just cleaned up the mouse pad, tried out two other mouse pads, cleaned the mouse with a qtip, etc. while reading the threads here and as it turns out my second monitor was plugged in but not turned on. at the very moment i turned it on the jumping stopped... 😉
i guess osx is confused by two screens and not be able to use the other. maybe some screen resolution stretching/unstretching for the mouse problem.

yep thats it!

I've had this problem happen alot in the last couple of weeks.. Sometimes a restart would have fixed the problem. I just ran across this post trying to find a solution, and it is the minidisplay port! My mouse was jumping like crazy, the moment I pulled out the external monitor, the mouse was back to normal....

I had the same problem and this solution (delete com.apple.bluetooth.plist and reset PRAM) solved it for me:
http://discussions.info.apple.com/thread.jspa?messageID=12039836

Hi,

I had the same issue and even got Apple to send me a new Magic Mouse, but when that arrived it starting happening again. I also have an Apple Cinema Display as a second Monitor. So after hours playing around and trying to pin point the issue I can confirm that for me the issue occurs when the second monitor is connected and switched off. As soon as you switch it back on, the problem stops. Now, I spent over £1300 on an iMac and £900 on an Apple Cinema Display, yet this £50 (overpriced) mouse causes all these issues, like others I rely on having good hardware and 2 monitors to do my job. The fact that Apple don't care nor do anything about fixing this issue only shows that their ability to charge extra high pricing for faulty hardware / software is becoming intolerable.

I raised a bug with Apple about this issue, it has been ignored.

Regards,

Iain

I also agree that it is a second monitor problem. The problem only happens when I turn off the second monitor after it has been recognized by my imac. Only then does my magic mouse cursor start to jump wildly. My particular setup is a Samsung 21.5 inch LED monitor which is attached with a mini display port to DVI cable adapter. My display adapter: ATI Radeon HD 5670 with 512MB.

I repeat when the second monitor is turned back on the mouse behaves completely normally. It also behaves normally when the second monitor is left off while the imac is booting.

I have to concur with Euphrosynus. I have had my 21.5" iMac for just over a month. About a week ago I added a second monitor (a 22" Acer) which is attached to the mini display port to DVI adapter. My graphics card is an ATI Radeon HD 5670 with 512MB.

Today I started having problems with my Magic Mouse jumping all over the place. I started looking for a solution and found this. My second monitor has been off all day. Since I turned it on, I have not had any problems with the mouse. Strange, but it seems to work.

This could help:

http://translate.google.es/translate?js=n&prev=_t&hl=es&ie=UTF-8&layout=2&eotf=1 &sl=es&tl=en&u=http%3A%2F%2Fwww.faq-mac.com%2F41961%2Fmagic-mouse-adaptadores-mi nidisplay-port-problemas-apantallado-cable

Is a Shield problem of the Minidisplay adaptor. Try with Aluminum foil.

Message was edited by: Carlos Burges

I unplugged my external monitor and the magic mouse skipping stopped. Apple should fix this.

Glad I read to the end of the thread.
This fixes it for me too ie Unplugged the mini display adapter, mouse stops jerking (and disappear/reappearing act).
I'd appreciate someone sending a picture of how they used silver foil to shield the adapter as described at http://bit.ly/fMcuca

Mine has just started doing the same thing. The curser is sluggish and erratic... Driving me nuts! I tried installing MouseZoom, but that hasn't fixed the issue, but perhaps made it worse!
Slightly relieved its not my dud mouse only. Perhaps a mouse flu?

Seems like it only started happening like in the past 2-3 months. I've had my iMac since March 2010.

If someone could let me know what I should do with the foil that would be awesome. Has anyone tried it yet? Does it work?

DJTrey,

I have no idea what I'm doing, but I had a go at using foil - this is what it looks like: http://i1212.photobucket.com/albums/cc442/furrytoes/minidisplay_foilwrapped.jpg

It didn't work immediately, but once I turned the 2nd monitor on and back off again, I haven't had the jittering since, and I haven't touched the others cords positions.