if you put a little oil in the cyl. then it would theoretically it would seal the rings causing the compression to go up if the rings were bad. If the compression does not go up then theoretically it would be the valves not sealing.
did you try adding oil or just adjust the valves... with zero compresion it owuld seem like you would eather have a hole in you r piston or a valve thats stuck open... but it seams that if a valve was stuck partially open then it would stll have some compression
