For LION only (Test only on 10.7.2) - Trackpad detects as Mouse with sidebar scroll for HP Elitebook 8540w (problematic Synaptics trackpad) or any other laptop that voodoo or other trackpad kext doesn't work on.
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Description: Trackpad kext removed from stock standard lion plugins folder in ApplePs2Controller.kext, forces Mouse to be used for trackpad . Also edited ApplePS2Mouse.kext info.plist for higher resolution for finer trackpad movement to match Display resolution is set for 1920x1080.


Install: Backup existing mouse kext's in S\L\E , then move to trash and install attached ApplePs2Controller.kext & AppleACPIPS2.kext in S\L\E using "Kext wizard" or similar kext tool. Repair permissions and update kext cache. (Note: AppleACPIPS2.kext is vanilla 10.7.2 kext, included incase you tried another mouse next as you will need it)


Tip: If you don't like the external trackpad vs external mouse speed balance use the mac system preferences "Mouse" pref pane + "mouse Acceleration" Pref pane or "USB Overdrive" to get the track speed under control. See attached sceenshot of mouse pref pane setting I used as generic without using any other mouse utilities (best for me)..
Also untick "Move mouse content in the direction of finger movement when scrolling or navigating" under System Preferences -> Mouse. This will get sidebar scroll on trackpad to move in the correct direction.
http://triq.net/articles/mouse-accel...-pane-mac-os-x (use leopard one listed as lion version seems to crash!)
http://www.usboverdrive.com/USBOverdrive/News.html (Great for customizing mouse buttons too, play with acceleration/speed)


Note: If anyone has a better trackpad fix for the Elitebook 8540w feel free to leave a comment with working trackpad kexts (I've tried voodoo + other home made kexts and none work for this model)


BigMacPlz - 2012