Can't help with the DTC. About the warped rotors... what are you torquing the lug nuts to? I've found in the past, that unless they're all torqued down evenly and at the proper spec. that the rotors will warp much easier. You've been around for a while so I'm thinking that may not be a factor, but...

How are the pads and calipers? Are they in good shape? Is the front end aligned properly? How are the tie rods and bearings? That's all I can think of off the top of my head. I suppose a couple bad sets of rotors could cause problems, but not as many as you've replaced.

Best of luck,
Marc