Remember to tag Jester's location - when you reach the cutscene where you see a frozen boat, Jester appears in the cutscene. Use cheats to go around the crack in the wall that reaches the frozen boat,and you'll see Jester not there.
In the first level, there is a balcony behind the command post. In the food shack, there is a radio on the ledge. Use it, and it will talk about why North Koreans evacuate the island of some volcanic activity.