More than likely it's being caused by a need for memory optimization, which still aren't fully implemented at this point as far as I know. If you're up for doing some more testing, lower your screen resolution (eg - 1024x768) and texture options and see if that helps you complete the game.
Regardless of the outcome, send your minidump file and a copy of your saved game to:
support@ironcladgames.com
... with a description of what you experience, and let them know if lowering the settings caused the issue to vanish.
