I'm green to this so perhaps this issue is simply due to my being a newbie... When I manually mark an object in a frame, usually the video automatically advances to the next frame. But sometimes it doesn't and remains the same one. If I click on it again (a second time, at the same spot), it will usually then advance, but that second click results in a new row of t,x,y data, which has a slightly greater timestamp (even though it was the same exact video frame). The frame number also increases by 1. This has me definitely confused. What am I doing wrong or misunderstanding?