Close the videos app completely and reboot the iPad. Go to the home screen first by tapping the home button. Double tap the home button and the recents tray will appear with all of your recent/open apps displayed at the bottom. Tap and hold down on any app icon until it begins to wiggle. Tap the minus sign in the upper left corner of
Reboot the iPad by holding down on the sleep and home buttons at the same time for about 10-15 seconds until the Apple Logo appears - ignore the red slider - let go of the buttons.
If that doesn't work - try this.
Swipe to the right from your first home screen to get to the iPad Spotlight search. Type in the name of any of your movies in the field at the top. When the movie appears in the search - tap on it and it should start to play. Let it play for a minute or so - hit done - go back to videos app and see if all is OK.