Gnome-MPlayer is only a GUI for MPlayer proper. Gnome Media Player is another
package.
I'd think that MPlayer is the perfect media player for your netbook. You
should be aware that MPlayer can be controlled with the keyboard. You don't
have to start MPlayer from the CLI. Make an association in your favourite
file manager for video files and point them to MPlayer. Then click on a file
and MPlayer will play it.
Sound= 9/0 up/down
Forward/Rewind= arrows
Pause= p/spacebar
Resume= p/spacebar again
Quit= Enter/Esc
Screenshot= s
http://www.mplayerhq.hu/DOCS/man/en/mplayer.1.html
For the screenshot functionality to work, you'll have to make a hidden folder
in your /home/user/.mplayer and create a file in it 'config'. Put a line
'vf=screenshot' there.
For Gnome-MPlayer, you have probably checked mute/audio output (Alsa or
something).