@Setanta,
I haven't researched this particular case, Setanta. But evolution is a gradual process, and that the line-drawing between the first
homo sapiens and her
homo rhodensis parents is somewhat arbitrary. So I'm
guessing there is some discrepancy in the definition of
homo sapiens that accounts for this 200,000 year difference. Discrepancies like this aren't so uncommon.
... and of course, there's always typos. Even in
Nature.
EDIT: Given the context in which the 400,000 years show up in the article, I think what they are saying is that the last common ancestor of
homo sapiens and
homo neanderthalensis lived 400,000 years ago. This common ancestor, or his daughter who is an ancestor of all
homo sapienses but no
homo neanderthalensises, would not necessarily have been classified as
homo sapiens by a taxonomist.