I bought my 104 yesterday (19/12/04) and this hack works. It took a couple of goes cos the remote isn`t the most responsive but keep at it cos it does work:-
Turn Player on
OPEN using remote
Press SETUP
Press volume buttons UP, DOWN, UP, DOWN
Press the RIGHT button
You will notice a number appear towards the top right of your screen (2 i think).
Keep pressing RIGHT until the number changes 255
Press SETUP to exit
Your player will now be region free
:D