Erratic or jumpy Might Mouse - MY SOLUTION

My wireless, bluetooth Mighty Mouse has been erratic or jumpy for a while now. Many months. The problem is intermittent, and would come and go apparently at random. All the while I was using the same 24" iMac (2.16 GHz Intel Core 2 Duo), the same Apple wireless bluetooth keyboard, the same grey fabric mousepad I've been using for years. I even upgraded from 10.4 to 10.5, and the problem persisted across the upgrade.

I switched back to a wired mouse for a long while, because the mighty mouse was unusable in this state, and just started using the mighty mouse again yesterday. The wired mighty mouse has never had this problem. Problem resurfaced with the bluetooth mighty mouse today.

I've read a HUGE number of posts and questions on this topic in these forums. I don't use iStat. I don't have airport turned on for this iMac, although I do have an airport extreme attached for use with my MacBook in the rest of my house.

I found a solution, that is working at least temporarily for me. I thought I would share. Your mileage may vary. Let me describe what happened.

I read some posts about the laser being "too powerful" and moving the cursor even when the mouse was lifted off of a surface. I also read a post about using only 1 battery in the mouse, instead of two. I was not aware that it would even work with just the one battery, but it does.

I decided to try some experiments. The jerky motion was extremely bad. My mousepad is grey. So I tried a white piece of paper instead of the grey mousepad. The jerky motion was even worse ! Off the charts unbearable. Then I tried a black piece of paper instead of the mousepad. The jerkiness was gone ! This was reliable and repeatable. I could switch the surface color, and as I switched the surface color from lighter to darker shades, the jerky motion went from horrible to non-existent.

Then I removed one of the batteries in the mighty mouse. With one battery, the grey mousepad gave smooth motion. I tried white paper with one battery, and the motion immediately became jerky again. Going back to the grey mousepad, motion was still slightly jerky. So I switched the mouse power off, then back on, and the motion was smooth again. The return of the jerky motion is repeatable when using a white surface is repeatable, even with 1 battery.

I had tried switching the mouse on and off in the past, with no success. I had also tried turning bluetooth on the iMac on and off in the past, also with no success.

Here are my recommendations:

Try a dark black surface.
Try using only 1 battery in your mighty mouse. This may enable the use of lighter colored surfaces.

I am using both of these steps right now, and have not had any jerky motion for an hour or so. Don't know how long this will last.

This problem did not exist when the bluetooth mighty mouse was new. I have cleaned the optical sensor on the bottom of the mouse, this did not seem to make any difference. I don't know why this problem should develop over time. I cleaned the scroll ball once when it would scroll down but not up, that was easy and have not had to clean it since.

That's it. I'm hoping this will last, and I hope this helps someone. I also hope this info helps Apple track down the root cause of the problem and fix it.

- Alan Feitelberg
Niskayuna, NY