Ok... so there may be several reasons but most probable is that in that third part of movie you have something more complicated like a 3D model, raytraced 3D text or something? Is that correct? Or 100% of movie is with the same kind of of effects?
It's completely the same all the way through. It's just a music thing so there's about 30 songs with an audio visualisation in the background, so the effects are the same all the way through.
This sounds rather unusual. Sorry you're experiencing this phenomenon. Not sure exactly what is going on here. I'd check the following:
- Check compositon settings > 3D renderer and make sure you're in "Classic 3D" mode.
- In AME make sure GPU acceleration is enabled.
- Reboot the computer after encoding the first few files
Sorry I don't have better troubleshooting steps for you, but if you try these, please let us know if they helped you solve your issue or not. If not, we can try another approach.