Ran across this and thought I would give you guys the correct answer from a commercial printer… Pantone spot swatches (pantone+ solid coated or solid uncoated books) should only be used when printing in spot color, they are not designed to print process but rather to look as much like the spot color as possible (thus the Lab definition). When designing to print in process you should use the “pantone+ color bridge” swatches. These colors are the closest approximation to the spot color that Pantone could create using CMYK. We see this every day, I wish Pantone had kept things the old way, it was much easier for the prepress guys! Your printer should be able to do a global change to fix the colors in the final pdf stage as we do daily…

…another side note, if you are printing digital (Indigo etc..) leave it set to the spot definition. The rip in the indigo actually matches spots better than the color bridge definition from my experience.