You have to admit that a TV is not a PC. You have to inspect the SRT file and see that it's perfect. VLC Player is well known to accept less than perfect content.
In my Samsung LCD TV (LA40C5301R), when I play AVI files (via the USB port) with associated SRT file, then the subtitles appear fine, but only for the first 25-30 minutes. Then they dissappear. If the video is longer than 40-45 min or so, subtitles reappear. I have checked the SRT files and they play fine in VLC player on my laptop and via the USB of DVD player (ie, no problem of missing subtitles in either case). I am keen on using the TV's USB for video files as it has better picture quality then via the USB port of my DVD player. Please can anyone suggest any solutions?