How to get rid of different mouse tracking speeds on dual screen setups I am using a MacBook Air 11" 2011 Model with Mac OS X Lion hooked up with a Cinema Display 27" and I am getting two different mouse tracking speeds (I am using a Apple Magic Mouse) when I move between the two screens in a two screen setup.

I have to move the mouse 20cm to move the cursor from one end of the 27" screen to the other.

However, I have to move the mouse 40cm to move the cursor from one end of the 11" screen to the other!

I can only adjust the mouse tracking speed in the system preferences, increasing it does make it faster on the 11" screen, but makes it too fast on the 27" screen...

Anyway I can fix this? This issue did not occur when I was running a MacBook Pro 13" when Snow Leopard and the same 27" screen.
I don't think you can. Read this article on TUAW:


  
    that's because the mouse speed option cannot be set on a per-monitor basis. Mouse tracking is controlled as part of system defaults, in the Universal Access preferences pane.
    
    The actual preference is called mouseDriverMaxSpeed and can range as an integer between 1 (lethargic) and 32 (zippy). Here's how you'd read the current setting from the command line:
    
    defaults read com.apple.universalaccess mouseDriverMaxSpeed
    
    Whatever number you set to feel right on one monitor will either feel draggy or hyper on the other.