hey guys i have a sony model vgn-fz340e ... it has a hdmi out .. core 2 duo, with 3 gb ram and also 320 gb hardrive.... but i cant hardly rent or buy hd movies in itunes and not sure why?> they are greyed out like when you pull up all hd movies and spiderman 3 is the first thing to rent or buy it says buy in hd greyed out and the standard version below it .lets me by it /....... what can i do ??? i dont understand it??