Thanks for your ideas. In aperture priority I was comparing the shutter speeds (e.g. LV = 1/30 and VF = 1/60). In shutter priority I was looking at the aperture (e.g. LV = 4 and VF = 5.6). These are just a few representative cases I have observed. Occasionally both methods will jive...but that is maybe 10% of the time (perhaps less).
My first inclination was that the camera was in auto ISO mode just as you suggested, but that was not the case. I also thought that perhaps the exposure compensation might be set independently for LV versus VF, but that is not correct either. I have tested this in controlled lighting conditions so variances in lighting are not a contributing factor.
I want to make sure there is not some other setting unique to the D800 that I am overlooking. I also want to make sure I do not have a faulty camera that has an issue with the metering system.