I just installed some Seymour Duncan Antiquity mini humbuckers in a SG -- got it all together tonight but I am hearing hum on the bridge and neck pickups (alone), but the guitar is dead silent in the middle position (both pickups). Two-conductor wire, no fancy switches. I followed the diagram from Duncan. All else equal, what are the likely culprits of this noise, or is it possible that they are just "that way," as some humbuckers are? They sound big and full, so I don't think I'm hearing only one coil on either, but I find the hum cancellation in the middle position a bit odd. What should I check first? I can send a picture but it's pretty cramped in there!