Player hangs when playing videos

Sometimes my player hangs when I'm trying to play videos, I've converted the videos using MZ Video Convertor. And when it hangs, I can't restart it using the reset, i.e. holding the Enter button for 10-20secs, it just simply has no response. Anyone has any idea why?

I can only wait for the battery to run flat then I can use it again.

You may need to hold the reset button longer. Usually if the video hangs the player it is a conversion problem. Try using one of the other conversion programs mentioned in the forum like SmartVD or PocketDivXConverter.