tomb raider legend - please help!!! im stuck!!

[missjef]

i'm on the first mission in bolivia and am in the room with the crates, i read a walk through quide which said the door should only open half way but its opened fully so i cant get to the alcove where the gold is, and the door i came through shut, so i have no way of getting out. i tried to go through the big door but it cuts to a film bit of the floor openning up and lara being sliced up, so i really dont know how to get out!!! please help!!

many thanks.

[j2buttonsw]

spoiler here: http://www.tombraiderchronicles.com/tr7/walkthrough/index.html

[j2buttonsw]

The crate puzzle - There is a movable cage close to the Reward and two more below. There are also three pressure plates, which means that each cage must be positioned on a plate. In fact, you need just two, as Lara can step on the third plate. Move the first one that is close to the plates. To put the other one on the upper level, you need to use the ramp on the left. Position the cage on the ramp (to the side that is closest to the entrance). You need to jump on the other side of the ramp and flip the cage on to the top level. You can use the steps at the end of the ledge in the middle of the room and jump on the ramp .

If you want the Gold Reward, you need to position the cage on the middle plate. The camera shows that the stone door is ready to work. Now step on the left plate (if the entrance is to your back) and the door will start opening. When the door is half open, step off the plate. The door will remain half open, which will give you the access to the Reward.

(Note: You may encounter a problem here. On stepping on the plate, a cut scene plays where it shows the door opening, blocking your way to the Reward. In that case, do not step on it. Either perform a low somersault over the plate or run past it diagonally, as hown in this screenshot. That way, the door will not open during the cut scene.)

Go to the back left corner (if the entrance is to your back) and climb on the ledge. Jump to grab the chain, then the opposite ledge. Traverse to the right and when you see another ledge above you, jump to grab it. Pull up and grab the horizontal chain. Swing to the other side and drop down. Hang from the edge on the right, release and grab the ledge below. Shimmy to the right and jump to grab the horizontal pole. Swing and jump close to the exit.