I have the same problem with audio as is described here:
When i play video_ts.ifo file its making just a ticking sound and the video is incredibly slow. But when i play vts_01_1.vob file the video and audio are great.
Im using Windows7, MPC 18.104.22.168 (rev72).
problem solved :-)
view -> options -> internal filters -> AC3 have to be checked.