I had this same problem on my old rig. I first tried to play this game last year and movies didn't work, same with the video calls, those were completely out of the picture, I just found out about them this time around when they actually happened. There were also other problems.
I believe the problem lied with my VGA card. Used to be an ATI Radeon 9600XT. Game was funky. Now I have an nVidia GeForce 9600GT and the game runs smoothly. With the updated version and the mouse mod.