Be sure to start your code with
import SimpleOpenNI.*;
SimpleOpenNI kinect;
Then, you use methods which don't exist anymore in SimpleOpenNI 1.96, check the doc. Since the big update of OpenNi/Nite, SimpleOpenNi is totally different:
enableHands() is now enableHand(),
addGesture(String) is now startGesture(int gesture),
removeGesture(String) is endGesture(int gesture),
startTrackingHands(PVector) is startTrackingHand(float[] pos)
Nite is not yet implemented in simpleOpenNi 1.96, so as far as I know, I think there are only 3 gestures you can use, GESTURE_CLICK, GESTURE_HAND_RAISE, GESTURE_WAVE