fixed issue #609
fixed issue #609

UManPychron/pychron,USGSDenverPychron/pychron,USGSDenverPychron/pychron,UManPychron/pychron,USGSDenverPychron/pychron,NMGRL/pychron,NMGRL/pychron,UManPychron/pychron,UManPychron/pychron,NMGRL/pychron,NMGRL/pychron,USGSDenverPychron/pychron