Sorry for the late reply; work has been hell this week. Alright, I try to shed more light BUT please bear with me. I have no technical knowledge in this.So then, naushan, can you please tell us, does your MKV files have subtitles or not?
If the answer is 'Yes they do', then do you have any MKV files that do not have subtitles that you can try and play.
My MKV files have subtitles. After the VLC loads the file for 1 minute, the video plays and shows subtitle. Oddly, when I use Mplayer (which I believe is phased out?), the file plays immediately and it does not show any subtitle when playing. I'm not sure if this is somehow conclusive to the same issue as Raziel mentioned.
I do have some AVI files but I have subtitles in .srt format and not ssa. When I open the AVI file and then later load the .srt subtitle file, the video does not slow or lag. Again, not sure if this information is relevant at all.
In case you're wondering, I was trying to play Valkyria Chronicles (I only have 2 epidodes - 4 and 6). Unfortunately I do not have any MKV files that does not have subtitle.
Edit: I tried out Mplayer Extended (rev 11) as suggested above, and found the following:
- First time I played a MKV file, it took 40s - 1 minute to load too, but subsequently it loads MKV files immediately
- I was able to fast forward by clicking on the play bar (unlike VLC).



