This e-mail exchange between Judd Apatow and Mark Brazill (creator of That 70s Show) is pretty funny. While Undeclared and 70s were briefly on FOX on that same time, there was talk of Topher Grace guesting on Undeclared, but Brazill wasn't consulted. He flipped ****, turned out he harbored resentment over thinking Apatow stole a show idea for a sketch on "The Ben Stiller Show".
Brazill: "Get cancer".
Apatow: "I think I'll wait until you get cancer and steal it from you."
Brazill: "See ya at the upfronts, *****! Well . . . unless you get canceled before that. Until then, die in a fiery accident and taste your own blood." (Sadly, Undeclared did get canceled before then...)
http://www.harpers.org/archive/2002/03/0079095