one day we faxed a client a business card proof. he called back later, saying that he liked the card, but he wanted it going the other way. i pulled up the file on my computer and asked him if he meant he wanted the card to be designed vertically instead of horizontally. he said that no, he wanted the card to be designed horizontally. as i'm staring at a horizontal card on my screen, i scratched my head and said i'd figure it out and send a new proof.
i pulled the actual printout we sent him so i could see what he was talking about. when i printed the first proof, the paper itself was horizontal so you had to turn it sideways to see the card. i simply printed out the same proof again so the paper was vertical. the client called back ten minutes later and said it was perfect.