I've been playing Army Of Two with my wife on the PS3 and we got stuck at on the level where you are supposed to take the monorail to your objective, but the doors just wouldn't open. We got so annoyed we ended up shooting out all the windows to see if we could jump into the tram. I then discovered a posting on Yahoo Answers which said after getting to the tram pause the game and then restart from your last checkpoint. It worked liked a charm! Restarting from last checkpoint places you directly in front of the tram entrance and you don't have to redo the power station level. Looks like a bug that shouldn't have got passed user testing at EA Games for the PS3. No one seems to have the problem on the Xbox version.