The Sensex opened with a positive gap of 25 points at 12,262, but soon slipped into red to touch a low of 12,218.The index has now rebounded into the positive zone and is now up 20 points at 12,257.Reliance Communications, Tata Motors and NTPC are the prominent gainers.HDFC Bank has slipped 1% to Rs 866. Dr.Reddy's is the other significant loser.