That was my problem - it wasn't in the extras menu, and 'mplayer' in xterm reported 'file not found'. So using Application Manager, I uninstalled, downloaded the .deb file to my memory card, and reinstalled. It is OK now, so the first online install must have been corrupted. I had the power supply plugged in for the original attempt. Is it a bad idea to do an install with the power supply connected? I thought I read that somewhere. Thanks.