I found the following region change hack for the Samsung DVD-R120:

Region code hack posted by Cloak, March 01 2006:
From Website:
http://www.dvddemystifiziert.de/codefree_en/samsung.html

Regional codes:
RC 1: 2, 9, 3, 3, 4
RC 2: 3, 8, 7, 6, 7 (or 5, 7, 5, 3, 8 )
RC 3: 5, 6, 7, 3, 2
RC 4: 7, 6, 8, 8, 4
RC 5: 5, 3, 8, 1, 4
RC 6: 2, 4, 4, 6, 2

1. Power on your player with no disc in the tray
2. Press REPEAT for 5 seconds
3. Enter the corresponding combination for your current RC (see top of the page)
4. Current RC should be displayed
5. Press the button for the desired RC (9=multi-region)
(Press OPEN)Power off your player

Unfortunately I can not get it to work. Once start typing the RC code, all it does is changing the channels on the DVD player. I do not see the RC number.

Am I missing something?