Blueshark

Hi! I'm using ver. 4.45. My newly created MP4 movie plays perfectly on my laptop. However, when I copy it to a memory stick and play it on my Sony Blueray DVD player (which has a USB port), there is no video, only audio played back. Other MP4s created from other software or source play without any issue. I have tried using another memory stick: same result. I am totally confused. Can anyone help? Thank you.