Streaming ITunes videos through LG DVD player

I have recently bought an LG Smart Blue Ray player - it does a great job of finding my Western Digital World Book and I am able to stream all my ITunes music. The player can see all my ITunes films and TV programmes however when I ask it to play a film it says the file type cannot be played. This, is very frustrating! Has anyone else had a similar problem and have you a solution? Many thanks.