How to get rid of different mouse tracking speeds on dual screen setups
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.