I've just find this fantastic forum for my Nas200. Thank you for your old thread. I've installed Jac4 firmware and succesfully patch Twonky Media Server. I need to use .mkv file on media server, but i've a strange problem. I put .mkv file on nas and this isn't show in file list of client (es windows media player). If I only rename the same file in .avi it appare in client file list and I can play it normaly Can you help me?