For a while my WD HD TV ( first gen) has stopped working whan I try to play mkv-files. I can star the files and play them for a short wile and then it turns into green, tha sound is still OK- If I press FF and then PLAY again it wiorks for a few seconds before goes wrong again. I Updated to the latest firmware and I think that that was when the problems started-
As I said I have the first version of tha player but it has been working OK for a year or more.