Try using a newer version of mplayer or mplayer2.
You did not provide which version or OS you use so I will assume you use Win.
Here are the links:
http://oss.netfarm.it/mplayer-win32.php
http://www.mplayer2.org/
Read the smplayer manual how to make the use of it.
If that does not fix it, try some options related to audio: e.g. change the output driver, disable the audio equalizer, etc.
Looking more at the log, it might not be audio issue but video, so you might try to disable (from Auto or Enabled to disabled) "correct pts" from Advanced options too.
Good luck.