>>95075029With Marvel or DC?
With Marvel, he had a fit over Quesada cancelling his X-Men: The Hidden Years comic and refused to do any more work for Marvel as long as Quesada and Jemas worked there.
With DC, at the time Superman Returns was gradually releasing info about the movie (like for instance the rumor that Lois' kid is actually Superman's), he was pissed off at it and banned all discussion about the film on his board. Then when the solicitations for the Superman Returns prequel comics were released, everyone noticed Byrne's name on the Krypton prequel and wondered what was going on since Byrne was adamant about his hatred. Byrne initially said that his project was basically based on the 1978 film (which was true; if you read the Krypton prequel it was basically a recap of the destruction of Krypton and Kal-El's arrival on Earth from that film) and then he suddenly announced that he was leaving the project (I think claiming that he was misled on what the project was). This caused problems because it meant they needed to get another artist to do it in a short amount of time. It's probably no coincidence after that that Byrne didn't get many other jobs at DC, then it dried up and he went over to IDW and also did commissions.