Animation glitch.

Two major glitches occur when I play an animation for this cloud:

  1. It blinks in when it enters the field of vision
  2. Black spots pop in and out on the material, like this:

These cloud animations are rigged to a skeleton. So far I think I am following standard operating procedure when importing animations and setting play speed etc. What could I be doing wrong?

Anybody know the answer to this one?