Stuck at level 15: The Infernal Machine

Hey,

This one has me stumped. I just arrived at chapter 15. I walk passed the gold slab, gently removed by the CIA, and I walk on, to the elevator shaft. I climb down the ladders to the bottom, and that's it. Nowhere to go but back.

Now I know I need to go through the hole acros from the ladder, but I can't. I need to jump to it, but no matter how much I jump, Indy won't grep the ledge. I search all of the path, but there's nothing left to do.

I even got as desparate as to download a walkthrough, but there is no mention of this problem (or how to deal with it!) in it. That got me thinking it might be a technical issue. Anybody know something?