Patch 1.2 DOES NOT patch the EXE file used to run the game, so YES, the v1.0 crack will work!
However, there are some people not able to load previous save games after patching to v1.2 (me for one) even after doing a fresh install, patching to 1.2 and copying the save files back! So head over to the FarCry Forums and read the bitching
Code:
http://ubbxforums.ubi.com/6/ubb.x?a=frm&s=400102&f=452106891