The IOC found that a member of China's women's gymnastics team in 2000 was underage and hence ineligible, which results in the disqualification of the entire team. That team had won the bronze medal, which now goes to the United States. At the same time, it looks like the IOC has cleared China's 2008 team of similar charges.
I have to confess, I had thought that the IOC would be too feckless to do something like this. It appears that I was wrong.