If you remove the faceplate of the Master Socket at the back of it will be six connectors.  There should be a Blue wire with White rings connected to connector 2 and a White wire with Blue rings to connector 6.   The Orange & White pair and the Green & White pair should not be connected.  
Those wires should go to first extension where they are connected to 2 & 5.  Another pair of Blue & White at the extension should be connected to 2 & 5 which go off to the next extension, etc., etc.  This is called "daisy chaining".
                
 T
                
 March 2009