Grain question

[IronFingaz]

Hey,

I got a Sony Bravia KDL40-W4500 and there seems to be a lot more grain in the picture whenever i watch movies. They look like grain bars across the TV. It was pretty bad on Robin Hood (2010), mostly the night scenes, so i tested the movie on my parents system and there was barely any grain in the same scenes. One scene can have a perfectly clear picture and the next it's grainy?
Does it have something to do with the setting perhaps, on the TV or Blu-Ray player (i use a PS3 and a Sony S360)?


Thanks