1.) Download this file: http://fxlegrand.free.fr/index.php?page=patches]this file
2.) Run the following in terminal (be sure to cd into the directory where you downloaded the file to first)
32bit Users:
sudo cp -p /usr/lib/wine/dinput.dll.so /usr/lib/wine/dinput.dll.so.old
sudo mv dinput.dll.so /usr/lib/wine/
64bit Users:
sudo cp -p /usr/lib32/wine/dinput.dll.so /usr/lib32/wine/dinput.dll.so.old
sudo mv dinput.dll.so /usr/lib32/wine/
Restart steam and then reload KF and you should be all set.
If your game crashes with a "General Protection Error" when you get attacked:
Go into the display options in KF and toggle "motion blur" off