To stop other others scratching their heads! can you add some relevant information to the board info.
This is :-
Both the GND strips by the SM pads are connected to the connector that plugs in to J5 pins 6&7 on the R2 board.
The GND strip at the end of the board connects only to J6 pin 7
Their is NO connection between these GND's until the board is plugged into the Firewing which can cause confusion when continuity checking !
Regards
Geoff