2MikeL: Seems like you use old non-optimal settings from stale '/home/user/.mplayer/config' file (sdl for video, esd for audio), it is better to remove it. Currently default options are stored in '/etc/mplayer/mplayer.conf' (this file should not be edited), you can override any of them with '/home/user/.mplayer/config' which contains your local options and has higher priority. And the command line options have the highest priority.

If you find that '-bandwidth 10000000' works best for you and don't want typing it every time you invoke mplayer, you can add it to '/home/user/.mplayer/config' in the following way:
Hope this helps.