I don't have this one, but I will cut you if you call them The Bearenstain Bears.
I am not crazy! I know they swapped those letters! I learned to read with Bearenstein. I knew it was Bearenstein. One after See Spot Run. As if I could make such a mistake. Never. Never!
I think a lot of us just mispronounced it. As an American "stain" seems like a lot less common of a name ending than "stein". Easy to gloss over a spelling in a long word.