The ad revenue from in-game/movie flash breaks down like this:
50% goes to you.
25% goes to NG (for hosting the ad servers that handle that stuff).
25% commission to the people organising the flash campaigns that appear.
I'm not quite sure what the in-page breakdowns are, but I would think the reason you're not seeing any revenue from there is because they're not getting enough unique views and clicks. If you have revenue sharing enabled and they do start meeting the right criteria, then you will see revenue from those.