I am having the same problem with Yosemite!! I have checked all the settings I can find. it is the randomness that is so frustrating. And not just with my Logitech trackball, but all with the built-in mouse pad.
[doublepost=1459307651][/doublepost]Hi,
I have been having the same problem. I've tried corded and cordless mice (made by Apple as well as the Yum Cha variety), reset v and p ram etc. Didn't work.
A solution seems to have been found – at least for the past 30 mins, it's been working properly.
I created a test user on my mac and my mouse was fine, so, you need to log back in under your normal user and . . .
Finder > press and hold down option then select Go from the menu at the top of the screen.
Select Library then scroll down to Preferences.
Inside this folder delete the following:
com.apple.AppleMultitouchMouse.plist
com.apple.AppleMultitouchTrackpad.plist
com.apple.driver.AppleBluetoothMultitouch.mouse.plist
com.apple.driver.AppleBluetoothMultitouch.trackpad.plist
com.apple.driver.AppleHIDMouse.plist
Then restart your mac.
Cheers,
Paul Zab
Postscript 20th April, 2016 . . .
The success of the above solution didn't last very long at all.
Solutions I have tried . . .
Changed mice e.g. Apple genuine as well as non-genuine mice, corded and wireless.
Reset pram and nvram.
Delete p.list preferences to do with mouse.
Reformat the hard drive i.e. delete everything on hard drive and re-install operating system.
Update operating system from Yosemite to El Capitan.
Mouse problem still persists.
I have talked to Apple support four times and the staff have been helpful as far as they can but they seem to think it is a hardware issue. Given I’ve changed mice three or four times and put the USB mouse connection into different ports on the mac AND I know these ports work because I use them for other activities i.e. connect camera and download photos etc. it certainly isn’t a hardware issue related to the mouse or the USB connection.
It seems that, somewhere between the USB connection and where the mouse is supposed to do something on the screen, there is a problem i.e. software engineering/operating system/coding problem.
Anyone else contact Apple support and/or can add anything further to my experiences?
Cheers, Paul Zab