musepack8: wrong currect duration

[ami_stuff]

it always resets to 0s after reaching 1,5sec

(musepack7 seems to be free of this problem)

C:\>ffplay musepack8.mpc
ffplay version N-40092-g3bbf3f7 Copyright (c) 2003-2012 the FFmpeg developers
  built on Apr 24 2012 00:55:38 with gcc 4.6.3
  configuration: --enable-gpl --enable-version3 --disable-w32threads --enable-ru
ntime-cpudetect --enable-avisynth --enable-bzlib --enable-frei0r --enable-libass
 --enable-libcelt --enable-libopencore-amrnb --enable-libopencore-amrwb --enable
-libfreetype --enable-libgsm --enable-libmp3lame --enable-libnut --enable-libope
njpeg --enable-librtmp --enable-libschroedinger --enable-libspeex --enable-libth
eora --enable-libutvideo --enable-libvo-aacenc --enable-libvo-amrwbenc --enable-
libvorbis --enable-libvpx --enable-libx264 --enable-libxavs --enable-libxvid --e
nable-zlib
  libavutil      51. 47.100 / 51. 47.100
  libavcodec     54. 15.100 / 54. 15.100
  libavformat    54.  3.100 / 54.  3.100
  libavdevice    53.  4.100 / 53.  4.100
  libavfilter     2. 72.100 /  2. 72.100
  libswscale      2.  1.100 /  2.  1.100
  libswresample   0. 11.100 /  0. 11.100
  libpostproc    52.  0.100 / 52.  0.100
Input #0, mpc8, from 'musepack8.mpc':
  Duration: 00:00:28.42, start: 0.000000, bitrate: 186 kb/s
    Stream #0:0: Audio: musepack8, 44100 Hz, stereo, s16
   0.34 A-V:  0.000 fd=   0 aq=  216KB vq=    0KB sq=    0B f=0/0