Have you used the accuracy in your zone? I removed that future in 2.0.5, but put it back with 2.0.6 and now it should work again like before.
This jumps are a problem with the Google Geofence Service which is used by the app. Like you said, it reports exits and entrances even the device is not moving.
Have you set the location to high accuracy?
Do not use a too small radius. I am using 500 meters.