[J.B. Books]

I am curious, one particular Parker I have seems to have the tendency of having the top lever return to the center position when the gun is open unless I push it right until I hear a distinct "click". When I hear that click the lever stays to the right. No other Parker gun I have does this, when the gun will open the lever will stay. What causes this malady that allows me to hear a "click" and only until I hear the click will the lever stay over to the right?