Since you didn't provide any details, I'm going to guess at this one. You used the word "print" which normally refers to paper currency; coins are said to be struck or minted. However, there aren't any 1924 one-dollar bills, so my first guess is that you're referring to a 1924 dollar coin. My next guess is that the "mistake" is the spelling of the word TRUST in the motto "In God We Trvst". The answer, as you can also find by reading a number of other posts on WikiAnswers on the same topic or checking the link below, is that this is NOT a mistake.