With this latest version I've seen a number of MKV files speed up the video while the audio continues normally and then skips ahead to catch up. Happens at arbitrary points in the playback, the only solution is to restart and jump to the location and try again which usually works but then the problem may occur a few minutes later. Fast forwarding at 1.5x seems to make this worse or trigger the problem. Could be a bunch of badly formed MKVs but they don't have any problem when played on a PC. Cheers.