Default DragonFace edit Allwinner firmware (touchscreen)

Hello guys. I have a problem on a tablet the touchscreen is reverse, if i touch on right the real touch go to left and vice versa. I found on internet software Dragon face for edit the rom. I downloaded the img file of supply and i try to edit (link http://moveontechnology.com/hugoenchina/?p=573). I know the link is in Spanish and im italian but the procedure are not clear.

however i know i need to change the value on system configuration :

ctp_revert_x_flag = 0
to
ctp_revert_x_flag = 1

i saved the file and save the rom, flash it....same problem is like not work the procedure. On the link there is another procedure for the INIT.RC

but i dont understand what i need to do. please help me