You probably have some slug after your show - press Sift-Z to show entire project and see if you can select the blank area or if there is a stray clip or slug down the timeline? Select it and delete it then press Shift-Z again...
Writer, Editor, Director
Unless of course you've got something connected to that slug. In which case the super intelligent FCP X will delete that for you too, because obviously that was your intention. :) Can of course trim it back.