only question is why administration has not said so ... US Treasury's Geithner says does not see China's exchange rate policy as posing a systemic risk but does pose problems...
No question China manipulates currency, that's the definition of a fixed exchange rate. The question is whether this is intended to give exporters an advantage. No one was complaining back in 1997 when China held up against a flood of devaluation in Asia, manipulating the yuan against the interests of Chinese exporters.
China have never denied that they peg their currency against the dollar. In fact recently, they came out and said they would let the yuan strengthen against the dollar. Probably because they know the US are going to print money and let the dollar slide. What's the difference? All government's intervene at certain times to manipulate their currencies.