The Hack for the Thomson 28WT25US Combination TV/DVD (probably work with the 24 and 32 versions of the set too) is as follows :
On the front panel of the TV/DVD Combo, press the "eject" (open/close) button, the "forward search", and the "OK" button all at the same time with a disc in the tray (Note : The tray must not be closed) .
The screen will appear to reset twice (refreshes the menu on screen 2 times) and will close the drawer, playing the disc.
This Hack is permanent and removes all region coding (holding even after power down).
If you wish to revert to just Region 2, repeat the hack.
**Note : Several attempts may be required to get the buttons pressed at the sam time - it not as easy as it sounds to get them pressed in unison!