Converting MTS to MKV - no subtitle

Converting MTS to MKV - no subtitle

I want to convert my .MTS videos from my Sony HD Cam into a .MKV. I am using ffmpeg and it works fine. But I have problems with the subtitles (in this case the subtitles are date and time) because they get lost once I convert the MTS into mkv.
I use this command:
ffmpeg -i 00235.MTS -scodec srt -acodec copy -vcodec copy -f matroska OUTPUT.mkv
This is the output:
ffmpeg version 0.8.6-4:0.8.6-0ubuntu0.12.04.1, Copyright (c) 2000-2013 the Libav developers
  built on Apr  2 2013 17:02:36 with gcc 4.6.3
*** THIS PROGRAM IS DEPRECATED ***
This program is only provided for compatibility and will be removed in a future release. Please use avconv instead.
Input #0, mpegts, from '00235.MTS':
  Duration: 00:00:22.07, start: 1.000011, bitrate: 26285 kb/s
  Program 1
    Stream #0.0[0x1011]: Video: h264 (High), yuv420p, 1920x1080 [PAR 1:1 DAR 16:9], 50 fps, 50 tbr, 90k tbn, 100 tbc
    Stream #0.1[0x1100]: Audio: ac3, 48000 Hz, 5.1, s16, 448 kb/s
    Stream #0.2[0x1200]: Data: [144][0][0][0] / 0x0090
Output #0, matroska, to 'OUTPUT.mkv':
  Metadata:
    encoder         : Lavf53.21.1
    Stream #0.0: Video: H264 / 0x34363248, yuv420p, 1920x1080 [PAR 1:1 DAR 16:9], q=2-31, 1k tbn, 50 tbc
    Stream #0.1: Audio: ac3, 48000 Hz, 5.1, 448 kb/s
Stream mapping:
  Stream #0.0 -> #0.0
  Stream #0.1 -> #0.1
Press ctrl-c to stop encoding
frame= 1104 fps=  0 q=-1.0 Lsize=   67284kB time=22.08 bitrate=24963.2kbits/s   
video:66061kB audio:1208kB global headers:0kB muxing overhead 0.023045%
It looks like Stream #0.2[0x1200] is the subtitle but in the end its not put into the MKV.
I hope someone can help me.
Kind regards