ffprobe failes to extract video bitrate for webm file

[Shital]

Not able to get video/audio bitrate for the attached webm file.
How to reproduce:

% ffprobe -v 9 -loglevel 99 video.webm
ffprobe version 1.1 Copyright (c) 2007-2013 the FFmpeg developers
  built on Jan 10 2013 12:21:46 with gcc 3.4.6 (GCC) 20060404 (Red Hat 3.4.6-9)
  configuration: --enable-gpl --enable-version3 --enable-zlib --enable-bzlib --enable-pthreads --enable-libvorbis --enable-libtheora --enable-libspeex --enable-libmp3lame --enable-libxvid --enable-libx264 --enable-libopencore_amrwb --enable-libopencore_amrnb --enable-libvo-aacenc --enable-libvpx --enable-libgsm --extra-libs=-static
  libavutil      52. 13.100 / 52. 13.100
  libavcodec     54. 86.100 / 54. 86.100
  libavformat    54. 59.106 / 54. 59.106
  libavdevice    54.  3.102 / 54.  3.102
  libavfilter     3. 32.100 /  3. 32.100
  libswscale      2.  1.103 /  2.  1.103
  libswresample   0. 17.102 /  0. 17.102
  libpostproc    52.  2.100 / 52.  2.100
[matroska,webm @ 0xbdd9220] Format matroska,webm probed with size=2048 and score=100
st:0 removing common factor 1000000 from timebase
st:1 removing common factor 1000000 from timebase
[matroska,webm @ 0xbdd9220] File position before avformat_find_stream_info() is 4490
[matroska,webm @ 0xbdd9220] Non-increasing DTS in stream 1: packet 16 with DTS 77, packet 17 with DTS 77
[matroska,webm @ 0xbdd9220] All info found
[matroska,webm @ 0xbdd9220] File position after avformat_find_stream_info() is 38937
Input #0, matroska,webm, from 'video.webm':
  Duration: 00:00:01.20, start: 0.000000, bitrate: 278 kb/s
    Stream #0:0(eng), 1, 1/1000: Video: vp8, yuv420p, 300x300, 1/1000, SAR 1:1 DAR 1:1, 25 fps, 25 tbr, 1k tbn, 1k tbc (default)
    Metadata:
      title           : Video
    Stream #0:1(eng), 18, 1/1000: Audio: vorbis, 48000 Hz, stereo, fltp (default)
    Metadata:
      title           : Audio
[vp8 @ 0xbde0ec0] detected 2 logical cores
[AVIOContext @ 0xbde18c0] Statistics: 41655 bytes read, 0 seeks

[Shital]

webm file from which ffprobe does not extract audio/video bitrates

[Carl Eugen Hoyos]

Also reproducible with ffmpeg.