The Ha Tam jewelry shop here sells foreign currency the way a filling station sells gasoline. So it was only seconds after pulling in on his motorbike that Quan Phan had swapped a fistful of Vietnamese dong for a neat stack of $100 bills -- U.S. $100 bills, to be precise. Developing countries -- and these days even developed ones like Greece and Spain -- constantly strive to retain the confidence of fickle foreign investors. Vietnam has a slightly different problem. Its government is struggling to restore faith among domestic investors like Phan. What makes Vietnamese nervous is the suspicion that the governing Communist Party will do anything to hit its economic growth target before a party congress early next year, even if that means letting inflation get out of control. To hedge against that possibility, Vietnamese have been vacuuming up gold and U.S. currency. Where do all those greenbacks go? Many go into low-yielding dollar deposits at banks. But another portion -- no one knows how many dollars circulate in Vietnam -- gets stashed at home. Safes are a popular household item in Vietnam. A recurring crisis for the Vietnamese, therefore, occurs every time the U.S. Treasury changes the security features on large American bills, and money-changers reject older varieties. High savings are a feature of Asian economies, one that economists say helps to perpetuate global trade imbalances and may have been a factor in the global crisis. Like other economies in the region, Vietnam is also a big exporter, the world's second-largest exporter of rice and coffee. And like many of its neighbors, it fixes the official exchange rate of its currency against the dollar. But Vietnam is still at such a comparatively low level of development that it has to import many of the manufactured goods it needs to keep growing. And while it exports oil, it has to import refined products for fuel. As a result, the country runs a net trade deficit. The dong has stabilized somewhat now, and credit growth has cooled. But Vietnamese investors and analysts remain skeptical that the situation has entirely stabilized, largely because efforts to control inflation are accompanied by statements from Hanoi supporting faster economic growth. Early next year, the Communist Party is scheduled to hold its 11th National Congress, a major period of political jockeying, analysts say. For government officials, they say, achieving growth targets is an important test. Last month, Prime Minister Nguyen Tan Dung predicted that GDP would not only reach the government's target but exceed it. 