Choppy Video

It's only a minor annoyance really, but the video cinematics in this game (such as the opening movie) keep stopping and starting when I try to watch them. It will play for a few seconds, then pause for one, and then continue etc etc.

The gameplay and any cutscenes made up of game footage work fine, but the simple video files will not and it has me confused. I can watch the opening movie fine on youtube.

I have dual graphics cards:
AMD Radeon HD 6620G
AMD Radeon HD 7450M
Drivers are updated.

Not the best cards but they shouldn't have trouble with video files.

I have the same issue but I just thought it was my laptop not really coping. I too have radeon dual graphics and more than enough RAM etc.