The job interview is not the place to confess your mistakes. It is not the time to demonstrate your weaknesses or let the interviewer know many of your faults. You will be asked about weaknesses, faults and mistakes for sure. These are traps, aimed at excluding you, and if you don't handle these questions deftly you will not get the job.
Think carefully about weaknesses and mistakes you are willing to discuss. Make sure you turn these answers into positives. If you have a weakness demonstrate that you manage it effectively. If you had trouble getting along with a colleague make sure it was for a darn good reason, such as someone not living up to commitments, and that you handled it appropriately for the benefit of the company.
The New York Times had a good discussion of this subject in an interview with Susan Docherty, who leads sales, service and marketing at General Motors.
Docherty explains how she hires:
"I’m always in hiring mode. Always. When someone comes in for an interview, and they’re polished, and they’re practiced, and they’ve honed their résumé — everybody can give a great first impression. But what’s most important is seeing how people handle interactions on a day-to-day basis, when you’ve got days that are good, bad and ugly. It’s about how you handle the day-to-day interactions with your peers. It’s about how you treat the people on your team."For more, see the complete interview.