I have a 2010 F-450 and experienced the same problem. In July 2012 went to the Ford dealer about ocassional excessive blue-white smoke from the tail pipe, which would only last for a few seconds. They said they know about this problem and Ford has a fix, which was to replace the coolant core. Problem continued. They ran tests and said I had excessive oil because the truck was manufacturing oil. They spent several days and talks with factory and determined I had a problem with the high-pressure oil pump. They replaced it. Problem continued. They then determined the defective oil pump caused problem with catalitic convertor and it was replaced. All this was covered by warrenty. Problem returned. Ford tech then told me that a little smoke is what these engines do at times. I went to a different dealer. They ran tests and determined that the regen cycle was not being completed. As we have been stationary for the past ten months, most driving occurs in and around town. Tech said computer showed it started regen cycle four times, but motor was turned off before completed. This will cause excessive smoke at times. I was advised to drive it out of town occasionally to work the motor so regen would be complete. As noted by others, the regen message appears and disappears quickly. Tech said when I see smoke manually check system reset to see if its in regen mode. If so, drive it, if not let them know. So far so good.