When attempting to play in reverse or switch video streams within a mkv file the playback will switch state to READY.  The pipeline can then be returned to the playing state but then if a seek is performed the pipeline will not resume playing.  

Switching video streams works the first time (although the pipeline freezes) but a subsequent switch plays then freezes after a couple of seconds. After this, the pipeline becomes unstable, sometimes seeks work, mostly stream switching works but the pipeline will often freeze after a second or so.

Sample video at https://dl.dropboxusercontent.com/u/2546412/13553200.mkv