System sounds disappear with ibrickr!!

[gimmeiphone]

so i used ibrickr to change a few of my system sounds, but iv lost my lock and unlock sound! i replaced it with a transformers one but wen i tried to revert back to the stock sounds i backed up, it just doesnt make any sound at all!! i want my clicky car door sound back lol. it still works with any other files i use just not the clicky caf. files, is there a way to convert caf. to mp3? maybe that wud work...