Have you connected the Ref pin of the buckpuck to +5v? (Assuming this is the buck puck: http://www.luxdrive.com/content/3021-BuckPuck.pdf)
Have you connected the Ref pin of the buckpuck to +5v? (Assuming this is the buck puck: http://www.luxdrive.com/content/3021-BuckPuck.pdf)