During a cleaning/fondling session with my old man's 24/7 Pro 40, I found that after dropping the slide with the slide release or sling-shotting the slide, the gun goes into double action mode. It will do this with an empty chamber or when chambering a round. However, when easing the slide home, it stays in single action mode. What the heck is going on? After dropping the slide, it should stay in single action, right?