Ok, I finally rented the game for PC. (But I will be waiting for the PS2 Version before I buy it.) I couldn't get very far, because the controls are driving me crazy.
I have started the walkthrough here:
http://tombraidergirl.com/indy6/gates.php
Very helpful hints can be found on another page:
http://www.cheatcodes.com/xbox/4738/hints.html