I am hooking up my laptop to my TV and extending my desktop and watching mkv's that way. Until recently everything worked fine. When I drag a movie over to the TV, the player just shows black. I can still hear audio, but there is no picture. I know there is a setting that I messed up...I just don't know what it is. Thanks.
Uh... are you on an SDTV or an HDTV? It might be that your .mkv is too high of a resolution for your TV. Try one of your old .mkvs that you know work and see if those play. It could be that, or a connection problem. How are your laptop/TV connected?
Sorry forgot to mention its an HDTV. I have tried old mkv's that I know worked on my old HDTV, but now they don't work on either. I have it hooked up through VGA from my laptop to VGA port on my TV.