Doesnt he? If I remember correctly his dad was a Slytherin. it was explained in the 2nd movie. the sorting hat in the first one was suppose to put him in Slytherin, but he was saying he wanted to go to...uh... o god i forgot.... this is not good... help? yeah so anyway the hat put him where he wanted to go even though he was suppose to be Slytherine (hence speaking snake language)
His dad was a Gryffindor. Harry was afraid of being in Slytherin with all the slimy kids, so he asked the sorting hat not to put him there. Lord Voldemort accidentally transferred some of his powers to Harry when he tried to kill him. I believe the hat was picking up on the scar and Voldie's transferred powers.
Nope... it's never been said WHAT house either of his parents were in.
Though, in the 1st movie, you see Harry taken to a plaque showing people who were on the Gryffindor quidditch team, and his dad got the seeker award!!!
:::>^..^<::: ~*~The Journey is more important than the end or the start~*~ :::>^..^<:::