If you start to fast forward quickly up to 16x or 32x and then press play to resume normal playback if this is done too quickly i.e. you didn't mean to do it in the first place or only want to skip a few seconds anyway then the sound and video end up completely out of sync. The sound continues from when you started the fast forward the video resumes from the point after skipping.
This does not occur if you let the FF continue for a few seconds.
Even more annoying is that after having to stop the playback ( to fix the sync ) you cannot resume from place last played and have to go all the way back to the beginning.