I had the same problem some 5 or 6 months back. the middle two lights would go off (link and data light of modem). several times i called the CC and technician came and couldn't quite figure it out what the problem is. I too didn't give up. I called again and again, but the same continued for about one month. But to my surprise, it got corrected somehow 😕😕.From then on, my airtel bb works fine without any disruptions 🙂.Try using USB cable to connect modem and comp.