question about VirtualDynamics Reference PC

I have recently been using a FLUKE 1711 to compare Power cables and power conditioners.I have tested the Shunyata Hydra V-Ray,a weizi,Burmester,and now the Virtual Dynamics Reference cables.I test the component for about 12 -24 hrs for good statistics.My wall voltage fluctuations are terrible,of what I tested,each have some distinct characteristics .Anyone interested in more detail can contact me. I have chosen to test the VD cables as they have a distinct sound in my system when connecting power amps,way too much boomy bass.What I am primarily looking at is the Voltage fluctuation and ground voltage which should be close to zero atleast under 2.0volts.With the exception of the VD cables all the measurements demonstrated an acceptable to excellent ground voltage. However the VD cables had a ground voltage of of approximately 55-60 volts,ie 50%of ground voltage,Any explanation???