I posted this as a reply elsewhere, but in case anyone needs help, I'm posting it as a new topic. I hope this helps you - it helped me after getting cutscenes freezing and going black!
The issue isn't necessarily your game - it's could be your PS3 config. I went into the video setup, and changed the HDMI output from 'Limited' to 'Complete' (it's on limited by default), and all my cutscenes now play perfectly, and as a bonus, the game loads MUCH quicker than before! Try it out, it worked for me!!