The reason CDU dropped substantially in Aug 2010 was because...

The reason CDU dropped substantially in Aug 2010 was because they finally released a JORC. One that many had been waiting for a long time. This JORC showed that the resource was not as big as thought, consequently the substantial drop in the value of its shares. If it had been manipulated as Maxw says, then it would have picked up a long time ago or been purchased by those "shorters". That it has not is evidence that it was not manipulated. Add to that the fall in the price of copper and the company still not selling copper many shareholders are selling and the selling will continue until the company has cash flow from the sale of copper or the price of copper goes up again.
I do concur with Maxw that naked shorting of stocks should be illegal, and that companies who hold shares should not be permitted to lend them out so that a hedge fund can sell them to bring the price down.