Ernie,
I know nothing about deer feeders, but I do know that deer in our part of Oregon browse on stuff within 2-3 feet of the ground, only reaching higher when they are desperate or for stuff they really like, such as cedar foliage. So your feeders may be too high. Our deer are smaller than some of those whitetails in the east, so what works there may not work here.
And as far as human scent goes, we used to see them browsing on freshly planted Doug firs at the bottom of the units while we planted the upper portions. Those DF's had scent on them from planting by human hands just a few hours before, so I would guess if they really like it, scent won't matter. And we had some pansies beside our driveway, 5 feet beyond the garage door and they took them down to the ground--I saw them doing it. They really like roses and blueberries, too, so if you have some, put your feeders among them.
Do you see them in your yard? Do your dogs scare them off, either by their presence or by their scent? Also, how much open space do they have to cross to get to the area where the feeders are? They like to be near cover. I would guess a good spot would be a little ways from cover but where you could still see them from your own hideaway.
Just some ideas.