i think your rfom is american. if not follow these steps.
well first delete save data utility and game data utility and then put in resisstance go to the first mission shoot round and then go to save and quit and hover over yes and den go play station menu and den eject the game and put in cod4 and then press "x" on cod4 and den wen the ps goes off automatically press "x"again on yes and it should start up and den just go in to a private match shoot around and den quit game and go into save data and copy over the cod 4 file to your usb and go too ps3 -> save data -> cod 4 and if u hover the cursor over cod4 it should say blus-00001 or something and put the codes in there and then put the usb back in your ps3 and copy the save data over then re-do the first part and go into the split screen just to test the codes and if they work go into a public match but remember to wait 20 seconds before you click play online because the downloading game settings sometimes patches the codes.
REP+
because that took me a while to write