Other than that, one of the worst I've knocked down uncovered a lack of assignment of IP (an early rich-media MUA) from a contractor that effectively meant the candidate company had zero value. "Who's Bob Smith of Bob Smith, Inc.? Can I talk to him about this shitty code? Oh, he owns it..."
What happens in that case? Does the acquisition stop in its tracks, or does the company try to contact Bob Smith and buy the rights?