Sometimes, external things that have absolutely nothing to do with you personally get in the way of the job offer or completely derail the hiring process. While, other times, the rejection is personal, possibly something you might have avoided.
For most job seekers, providing a list of references is an afterthought. The toughest part of the job search is over -- landing the interview and performing well enough to get to the "final four" (or five or...). Whew -- it's almost over! Not so fast!