As far as your first question, there must be a small snippet of video or audio down at the one minute mark. If you sctvate the return to beginning arrrow on the controls your cursor will go to the start. Correspondingly if you activate the go to end arrow where does the cursor go to? If it goes past what you think is the end of your video, there is something down there. You can expand your view of the timeline to magnify everything to find some little frame, etc. Alos its possible that you might have a marker down there. Delete whatever you find down there and you will now have a correct ending.