The Sensex at the Bombay Stock Exchange opened 44 points, or 0.2 per cent higher, at 18,264, this morning, helped by a recovery in auto stocks. But the Sensex has since given up all its early gains, to stand 76 points, or 0.4 percent in the red, at 18,144, a short while ago.Other Asian bourses in Japan, Singapore, Hong Kong, Taiwan, Indonesia, and South Korea were down by between 0.5 percent and 2.5 percent, after the US central bank's proposal to spur growth failed to ease investor concerns that the world's biggest economy is weakening.