Greg Mankiw had a good reasonable blog post on the issue of data error. The best single quote on the entire subject, however, comes from Caroline Baum in her most recent Bloomberg column "Reinhart-Rogoff Uproar Settles Nothing"
Forget the data for a minute. Imagine asking the average person on the street, Is too much debt a problem? Do you think you would get any negative responses? That’s the essence of Reinhart and Rogoff’s research. You don’t need a doctorate in economics to understand that you can’t spend beyond your means forever, or that piling on debt because it’s cheap to borrow isn’t sound policy.