Warped rotors, correct?

[Howie]

Do what Dan says, use brake cleaner and a a Scotch Brite pad on the rotors, or something like this   http://www.sjdiscounttools.com/vehicle-specialty-tools-brake-service-tools-brake-rotor-hones.html  you want to clean them and leave a non directional pattern , but not remove material.  Often, the pulsation is due to uneven transfer of brake material to the rotor.  If you have over 40K km on them you might also want to put a micrometer on them.  If they are below minimum thickness you need to replace them anyway.

Ducpainter's full floater idea may help too, do expect some low speed rattling if you do it though.