Code:
Option "ConnectedMonitor" "CRT, TV"
The order of which display device you name first is important here. Make sure you have CRT (your main display) first, and then TV (set as second display).
The problem with playing a movie on TV and it actually playing it with the monitor's resolution is because the TV will never be able to handle what your monitor could (I could be wrong here but at least I believe to be correct with this :P). For example my TV only can go as high as 1024x768 whereas my current 19" CRT monitor works just fine with 1600x1200.
You can either play a movie by moving and resizing "mplayer's output" around so it fits rigth on your TV's screen (including removing the titlebar which I'm not going to explain how to get rid of here because it depends also on what window manager or DE you're using) OR you can play around with
mplayer -vo help
and try different video outputs
I for example use
Code:
mplayer -vo svga filename.fileextention
and it full screens my movies right on my CRT and TV
if I want to play a movie on both display devices
Hope this helps!