OK I know there is a lot of info on this type of file, but I could not find the answer to my problem, basically I have a 720p mkv file, I have install ffdshow, and Haali Media, the mkv file will play in media player 11, (albeit jumpy) but not in media portal. Ive got 1gb of RAM and a athlon 2.6
edit. I've just tryed a normal .avi file same things plays in media player but not media portal
edit. I've just tryed a normal .avi file same things plays in media player but not media portal