Let's say you're a reporter in your first job and you've been asked to do everything. You're a one-man-band and you dream of a job with a photog. (You guys never thought the day would come when reporters would dream about you, huh?) You've also filled in as a producer, and that's something you really dislike.
So, you put all these duties down on your resume and a prospective employer looks at it and sees all your hats. "Hmmmm... we've got two openings for a reporter, and one's for a one-man-band. Looks like this person can shoot. Oooooh, and she can fill in as a producer, too!"
And just like that, you've got the same job you had before. Wearing two of the hats you'd love to donate to Goodwill. (And trust me, if they know you can produce, they'll stick you with that more than you can imagine.)
If you've filled in as a producer and hate it, don't put it on your resume. If you absolutely will not take a job as a one-man-band, don't put the fact that you can shoot on your resume. You're a reporter, or anchor, or both... and that's it. You've run the prompter, but that's not on your resume. This is no different.
Sometimes the less they know about you, the better. If there's something about the job you really hate, best to not let them know that you know how to do it.