Mouse keeps double clicking on 1 click

It seams that is not only a Mountain Lion issue. I have an 27" iMac late 2009 with OS 10.7.5 Lion.

Two weeks ago my Magic Mouse started randomly to double click with a single click. Tried different mice and disconnected the Magic Mouse - same troubles.

For disambiguation: "single click" means to press and release instantly the mouse button with the next click after min. 5 seconds.

To summarise the symptoms that occure randomly (every 3rd single click with Magic Mouse to every 10th to 20th single click with other mice):

1. a single click generates a double click (it occures even if you don't release the mouse button);

2. when you try to higlight a text it starts to select, then suddenly deselects and selects again or generates a text drag; it even deselects randomly the text after you release the mouse button;

3. when you drag a window it will minimise the window or release it suddenly and will continue to select or drag something else;

4. if you click on menu bar it will open and close instantly the menu item.

To show how single click errors occures I tried to draw with my Magic Mouse and with normal speed a vertical line in GIMP App from top (mouse left button press) to bottom (mouse release).

As you can see the Magic Mouse score is 5 errors out of 14 tries (with other mice the score is 5 times lower):

The 4th line shows a second "virtual" click between pressing and releasing the mouse button.

The 6th surprised with a quickest second click (with wired mice the second click is also instant).

The 11th a long disruption of connection before the second click.

No immediate mouse click response with 13th attempt.

The 14th generated a second click when I released the mouse button.

I've searched for answers. I've tried unsuccessfully:

1. to play with System Preferences in Mouse and Universal Access settings; When you change the Mouse secondary click to be on the left side, the double click errors are generated only when you click the left button or the left side of the Magic Mouse;

2. to use different mice both USB and wireless;

3. to delete a lot of files in ~/Library/Preferences/ and to restart;

4. to reset the NVRAM(PRAM);

4. to reset the System Management Controller (SMC);

5. to restart the OS in safe mode;

6. to perform the Apple Hardware Test;

7. to override accidental clicks with some third party App like MagicPref;

8. to replace/charge the Magic Mouse batteries;

9. to turn off the iMac bluetooth and bt keyboard.

... Any other suggestions?

Is this an Apple equation with no solution?

Perhaps it is Gimp or possibly the Magic Mouse, but you say you've used other mice, right?

Here is my try with Pixelmator and a Magic Trackpad.

Gray lines are tap to click.

Blue lines are physical click and drag.

Hi again,

I’ve SOLVED partly my double click issue except for my Magic Mouse. I’ve deleted/uninstalled all residual ItelliPoint and IntelliType files/software (installed 3 years ago for my old MS wireless keyboard and mouse).

Unfortunately my Magic Mouse still continues to double click with one click even if less often than before. Now it generates about 3 "double click" errors out of 20 single clicks.

At the same time, my Magic Mouse generates dozens of error messages in kernel.log like this:

IOHIDSystem cursor update overdue. Resending.

It seams that double click (short loss of wireless mouse connection) is a Bluetooth issue.

According to this post https://discussions.apple.com/thread/4344745 it could be a faulty iMac Airport/Bluetooth module.

I have the same problem, and have gone through the same attempt at troubleshooting and fixing the problem that the OP went through, with the same results.

It started on my home computer (don't have the specs handy; not at home) around 6 months ago, running 10.8.1 at the time and a wireless USB Logitech mouse. I switched to using a magic trackpad, and that worked fine, however some of the programs I need to run don't work great with a trackpad, so I started using a wired mouse and haven't had a problem so far. Not an ideal solution.

Now I'm having the problem with my work computer (iMac, 3.06 GHz Intel Core i3, 16GB RAM) running 10.8.2 and using an Apple magic mouse. It started about a week ago, and after starting the search for answers again, I still haven't found a good solution.

I just ran the update to 10.8.3, and tested by carefully single clicking on random files and folders. About one in six double-click and open, so it still isn't fixed.

Hi. I have OS 10.8.3 and an iMac late 2009. Is this the Magic Mouse itself and/or the bluetooth hardware in the Mac? My Magic Mouse would double click too, not always but often even if I just did a single click. How did you solve this? Also highlighting text, especially from left to right is messed up or isn't possible at times. Thank you in advance. Have a great sunday and a good sunday mass.

God bless.

Hi. This all came with a lot of hardwork and a lot of prayers (including daily mass, daily rosary, novena- the fix for the mouse included in those prayers but not solely the only one). I use Mountain Lion's latest build.

It seems to have solved itself, after trying everything as well ( reset pram and SMC, use my backup Snow Leopard on a USB external and I think at one time, use a Linux on my iMac) when I took my Magic Mouse to an authorized Apple repair center (was at a mall).

When they tried the mouse there, it was confirmed by the technician, that it would double click every 100 clicks. It was never fixed in short. I was ready to buy another mouse from Logitech with dark something sensor (which will work on my huge custom designed glass table (my design) without any translucent thin pad or any non-glass pad) because the Magic Mouse is almost as expensive be a that Logitech mouse so I don't end up with two Magic Mouse.

Thanking them, I went home but it the problem was fixed. I tested it more than 100 clicks and thoroughly tested it again to make sure.

My theory is there might some malware or bug in OS X Lion or Mountain Lion, that's affecting the firmware of the Magic Mouse. I have a backup Snow Leopard because things were a lot more stable with Snow Leopard, which may be the best version when it came to stability. I upgrade because there are UI enhancements with every version and some apps like iTunes will only work with newer versions by default. Also Snow Leopard, even though it's more stable is not that significantly stable than Lion or Mountain Lion which occasionally crashes too but it's not that bad vs. the UI enhancements and compatibility which are more valuable overall I believe.

I guess prayers and science is a powerful combo:)

Thanks. I hope this helps. God bless.