The Associated Press reports that an inmate who served 20 years of a life sentence was exonerated when the complainants, who had been six and four at the time they testified, revealed that they had been coached by a relative to offer false testimony. http://www.thebostonchannel.com/news/3892857/detail.html
Another blog reports that the case was prosecuted by the now-governor of North Carolina–although prosecutorial misconduct does not seem to loom large in the case.
As is so often the case, there is an article on SSRN offering insight into the general phenomenon: See Schuman, John Philippe, Bala, Nicholas C. and Lee, Kang, "Developmentally Appropriate Questions for Child Witnesses" Queen’s Law Journal, Vol. 25, Pp. 251-304, 1999 http://papers.ssrn.com/sol3/papers.cfm?abstract_id=198969
And here’s an alleged exonerating DNA test of an Israeli inmate of a rape charge; he had previously pleaded guilty to an earlier rape.
Jack Chin