Video Problem for sandisk sansa e250. Please help

Hi, I have a problem with the video for the sansa e250. I play a video on my sansa and it doesnt play all the way. it cuts off at half way and goes back to the menu. Its a music video. only like 4 minutes long. Does anyone know what I can do to fix it? please let me know. thanks

does it always cut off at the same spot? Im assuming you can watch the whole thing on the computer without an issue.
Do other videos do the same thing?