Arduino Uno R3 Bluetooth Shield is not discovering in any of the device
As per this site: http://www.rjanick.com/2012/11/26/seeed-studio-bluetooth-shield/

Try switching the #define rxd and #define txd pin numbers in the code, inversely corresponding to the ones that the jumpers are connected to on the board.

For instance: my pins are jumped from the BT_TX line to digital 6 (and BT_RX to pin 7), so in the code I write #define TxD 7, and RxD 6. This made the board's LEDs blink differently (red blinks on D2 until connection).