iron ore results and decline in share price

I am just researching this stock which i think does have some promise..but i am not totally convinced at this point...given the current low levels of resource and building in the very risky ventures in the USA with uranium the SP may fall further.....besides the usual impacts of overall market falls...why has the SP dramatically fallen by over 50% since the big iron ore announcement in Dec 07...was there something i missed in the announcements....is the fall due to entry into the USA.