I'm still fumbling my way through pickups too, but many Dimarzios have to be reversed. I put a set of D Activators in a JS and you have to reverse one of them. I had a hell of a time putting an
Air Norton and a Fred in another guitar that was an HSH. In that case the two humbuckers had to be the same and the single coil had to be wired a bit different. I was very aggrivated because the import switch didn't seem to be working very well (and I think the previous owner had put a TAD BIT too much solder on everything). So we bought a new switch and tried a nice Cruiser inbetween the two and it turned out pretty badass.
I've seen a hundred different wiring diagrams and the only thing I've figured out is there is no real answer. Trial and error seem the best solution. Just keep close track of what you have tried.
If you find a good single coil, I'll see if I can crack open the 7dbk and sketch the wiring as an example for you.