With the "Display speed" option enabled, the K2 records the current speed within the video.
As the speed is measured by gps, it takes some time from startup till the speed is show. During that phase, the recorded (and shown) speed is simply 000. That´s absolutely ok.
But if the gps reception fails while driving, the K2 simply holds the current speed. This leads to situations where I am e.g waiting at a traffic light, but the K2 still shows "70km/h" in the video. Well...while it is obvious that the recorded speed isn´t correct in this situation, this behaviour of the K2 can cause inconvenience in other situations.