Over 5 editions of 40k a lot of things can change. Sometimes GW clarify and develop the back story, other times they ignore completely what has been written before. Then there are those times when the writers just seem to go off on one down the merry road of "I'm gonna change that guys name now" (Ranek/Ulrik)

What are the infamous instances when fluff has changed dramatically from its original source, or stuff that doesnt add up? And just what colour is Ragnar Blackmanes hair??