Colours flicker in and out for no apparent reason?

http://www.youtube.com/watch?v=5R391WkVmug

You can see on certain frames the colour of some of the heads disappears for a frame and caries on to flicker on and off throughout, while the outline and the colour of the rest of he body, which is all part of the same skin group, remains uneffected.

How can I fix this?

There is not enough information… Please contact Support@toonboom.com for this.