switching subtitles in matroska

[kea]

When playing a matroska file with several subtitles tracks, switching between tracks doesn't work well. You often have to do a small backward jump after a switch so the subtitles are displayed. It seems to be specific to matroska, cause I've tried with AVI and it worked perfetly well.
Oh and also, the language tag of the subtitle track is not display, but maybe it's not yet supported.
The matroska file has been made with mkvmerge 0.8.2