Unfortunately, I don't know what the "IGM level" or the "map command" are. I'm not using any cheats.
However, I can see part of the problem in the visual walkthrough at http://www.visualwalkthroughs.com/el...2/ig2/ig2.htm.
In the last image, I can see the shuttle that Chell is working on. It is at floor level. However, in my game, the shuttle is lowered down into its bay, making the rear entrance inacessible.
Is there something that should cause the shuttle to be lifted out of its bay, to floor level?