Freezing episode iii chapter 4

[Chicken_Assassin]

in the level with yoda and the wookies, i think its chapter 4 of episode iii, everytime i get to the part where i have to grapple with chewbacca, and i hit the button it freezes. anyone know what the problem may be?
edit: i have the pc version.
also: where is the e-mail submission form that is supposed to be at the eidos support site? i cant find it.