Why is my animation twitching every time the first frame plays? (video now available)

I have a book with an animated flipping page. Whenever the animation plays in the viewport, it makes a bad twitch at the first frame. I know it is the first because I tried a delay after the animation before it loops again. I tried deleting the last frame in 3ds max, make a last keyframe identical to the first, and none worked. Anyone else had this happen?

Video of problem