Did you soak the pots overnight? What depth were you fishing? Where you fishing with the crowds? The basic rules I follow are: Experiment to find the right depth...if you are catching rocks, the dungies are likely deeper. fish the slack tides, and stay away from the crowds.
Kramer makes good point about tides. During the strong tides, crabs will "dig in" to the sand and are less inclined to move. Also, the scent tends to get carried away quickly in the strong currents. We set pots on Friday in Area 10 during the strong afternoon incoming and only got a few. The pots were soaked overnight (during small tides) in the same area and had multiple limits of legal males the next morning.
Also, this year where we fish the crabs seem much deeper than normal. My usual haunts in 75 feet have produced mostly rocks, but pots fished in 110-120 feet have produced well.
Finally, I like experiment and try to fish where the other pots aint! I have set pots randomly in different areas of Area 10 over the last few years and have found that there are the "hot spots" where most everyone sets (these get picked out quick), and then there are many areas that dungies frequent which almost never see a pot. I currently fish an area with consistent success that is within one mile of my home harbor. This is a spot I drove directly over for years while running another ten miles north to crab!