Couple of possibilities:
1) The work area bar (WAB) could be extended past the end of the movie. The WAB is the grey bar above the timeline with handles on each end. Drag the handle so it just covers the movie.
2) You have a fragment of a frame out past of the end of the movie... possibly left over when you cut it. To see if this is the case press END on your keyboard to go to the end of the movie or press PgUp or PgDn to go from from clip to clip until you get to the end of the movie. Then zoom in and see if there is a frame there... if so delete it.
I had the WAB bar set in the right place, but by doing page-up and page-down I did find some snippets of soundtrack that had got seperated. They weren't actually visible in the zoomed out view - so I didn't realise they were there! Thank you very much for the help
Glad that you found the "orphans." Also, nice use of PageUp/PageDn. These two keys are so very often overlooked.
Two things that I do, when I *think* that editing is done is to hit the "\" [Backspace key] to see the full Timeline. Often, orphans will show up there. Next, I compare my runtime to make sure that everything matches up. Hitting the End key will also often expose the orphans.
Good luck, and thanks for reporting. Also, that section without any Video can also cause a new set of problems when one goes to Burn a DVD.