on BBC refusing the prize is h3r3 : http://news.bbc.co.uk/2/hi/science/nature/5274040.stm
QUOTE from wikipedia:
“As of the spring of 2003 Perelman no longer works in the Steklov Institute. His friends are said to have stated that he currently finds mathematics a painful topic to discuss; some even say that he has abandoned mathematics entirely. According to a recent interview, Perelman is currently jobless, living with his mother in St Petersburg.
Although Perelman says in The New Yorker article that he is disappointed with the ethical standards of the field of mathematics, the article implies that Perelman refers particularly to Yau’s efforts to downplay his role in the proof and play up the work of Cao and Zhu. Perelman has said that “I can’t say I’m outraged. Other people do worse. Of course, there are many mathematicians who are more or less honest. But almost all of them are conformists. They are more or less honest, but they tolerate those who are not honest.” He has also said that “It is not people who break ethical standards who are regarded as aliens. It is people like me who are isolated.”
This, combined with the possibility of being awarded a Fields medal, led him to quit professional mathematics. He has said that “As long as I was not conspicuous, I had a choice. Either to make some ugly thing” (a fuss about the mathematics community’s lack of integrity) “or, if I didn’t do this kind of thing, to be treated as a pet. Now, when I become a very conspicuous person, I cannot stay a pet and say nothing. That is why I had to quit.””