The box can be pretty picky about SRT files. Make sure the file is ANSI encoded (UTF-8 is probably ok, but I haven't tried it) and one thing that's sure to cause a problem is if the last line doesn't end with a new line character. If I have a file that doesn't work I open it in Notepad++, change the line endings to Unix format, trim trailing space, and make sure I go to the last line and hit return if necessary. One other thing in case you didn't know, the SRT file has to have the same name as the video file, just with a .srt extension.
I'll take a look at the MKV stuff you added and add it to the beta 2.0 version I've been working on forever. MKV support was initially only for USB devices, so I haven't even tried to stream one.
Interesting idea about shutting down the server. I don't know if that's possible across all OSs, but it should be possible for Windows at least. Until I moved everything to my Dockstar which I just leave on, I used Wake on LAN and VNC to control my server from a laptop.
-JT
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