I Am Not Spock: This briefly happened with Reese Witherspoon, whose performance was so convincing that she had trouble getting work for a few years, since producers thought that her performance was indicative of her Real Life personality. She's since broken out of this typecasting.
Reese Witherspoon originally wanted to play Tammy.
The director wanted more than anything else to edit the climax of the film In The Style Of the final showdown from The Good The Bad And The Ugly. His editor, however, was willing to sacrifice part of his paycheck so that he wouldn't.