I have recently hooked my MB white, 2 ghz to my Sony V5500 with a hdmi cabel and getting an output of 1080p. Now i want to play video files from my computer on my tv in full hd. But everytime i try loading a 720p video file, mkv format, it starts lagging. Not much, but enough for me to get annoyed!! Is this a hardware issue? Is my macbook not powerfull enough for this task? Please help...