This is the correct and best answer. It works. It is posted by “@Buyin” above. Another individual commented that it doesn’t work. He is wrong. It works, I’ve confirmed it. It restores the three finger vertical swipe to switch between interface and implementation files (.h and .m) in xCode in Lion.
From your terminal:
Change to appropriate directory (note, if your Library dir is hidden, in the terminal just type the following: chflags nohidden ~/Library )
1. cd /Users/YOURUSERNAME/Library/Preferences/ByHost
List files so you can see the .GlobalPreferences.XXXX-XXXX-XXXX-XXXX.plist
2. ls -lah
Open that plist file in xcode
3. open -a /Applications/Xcode.app ".GlobalPreferences.XXXX-XXXX-XXXX-XXXX.plist"
Set value to 1 for the key “com.apple.trackpad.threeFingerVertSwipeGesture”
Save the plist file
Log out and back into machine
VOILA!