IPod nano video help, it's in .mp4 and everything should work, but..?

I used iTube [Ares Tube] and it downloaded the video to my iPod. I see it's thumbnail on my iTunes library and it's in my menu on my iPod, but when i select it, the screen just turns dark and it doesn't play. I can skip to the middle of the video BUT it just puts it back to 0:00 and the screen stays dark. How do I get the video to work??