Do you believe I am unaware of this? It works since the coefficient is positive. This information can be found inside datasheets.
Here's also a circuit where I use a LED to get the right voltage level for digital inputs.
http://arduino.cc/forum/index.php/topic,96189.0.html
I have read the complete thread again, looked at the photos and I saw the videos.
Seems to be it is a white backlight and they don't draw as much power as the green one's.
If the brightness is moderate then it is OK no extra parts are required.
Here is someone using this LCD without microcontroller:
http://iamsuhasm.wordpress.com/tutsproj/using-lcds/ (in 8bit mode)
They are also having problems (with the connections):
http://walkingwithtux.wordpress.com/2010/05/01/jhd162a-lcd-display-3-wire-interface-with-arduino/