I assume when the game froze you tried hitting all the buttons, and (if possible) saving the game to a new slot and reloading?
Are you playing the game off the DVD or do you have it installed on the hard drive (if available)?
Try emailing support@larian.com, with a description of the problem, and maybe a link to this topic. With a save before destroying the last generator they may be able to fix the problem, assuming it is in the save itself and not with the DVD (ie a scratch making this cutscene data unreadable, or something). You're already familiar with at least part of this, but here are some instructions for
emailing an Xbox save.