You say it's a scene where "Shepard and Ashley" watch the view. Is Kaidan in your squad? He's supposed to be there. If he's not, that's probably the cause of the problem.
no, I have the same problem and both Kaidan and Ashley are in my team...I think the scene can only be triggered when they both are there anyway. still the game seems to have problems loading the answers you can give during that scene. I had that problem also during an earlier playthrough, though in that case restarting the game at another day resolved the problem.
Edit: Yup, restarting the pc solved the problem again.
