After yesterday's mammoth 561 point gain, the Sensex at the Bombay Stock Exchange fell 92 points, or 0.5 per cent, to 17,238, in opening trade, today, on emergence of profit-booking by investors, and a weak trend on other Asian markets. Falling further, the Sensex stood 121 points, or 0.7 percent in the red, at 17,209, a short while ago.Other Asian bourses in Japan, Hong Kong, China, Indonesia, South Korea and Taiwan were down between 0.5 percent and 2 percent, amid lingering doubts about how Greece and other debt-laden Euro-zone countries will reduce their budget deficits.