[ham90mack]

We just got our IR receiver working yesterday, although it didn't work for signaling the controller at first since we used a separate 9v battery and the controller thought that it was always receiving a signal (something about a floating ground was the explanation... o_0). But once we connected both power and ground pins from the receiver to the digital input's power and ground, the board worked fine with no power problems. I wouldn't guarantee it to work with only one power and ground pin connected, but it might... Maybe they just said seven volts to guarantee that the board will work, or having two sources of 5v power allows the board to draw enough current to power itself since it has two places to draw from.