MOST NEWSPAPER EDITORS take for granted the crossword puzzle that runs somewhere in the back of their paper. Big mistake. Readers may forgive you if you lose a front-page jump or run a photo upside down. But leave out puzzle clues or put in the wrong solution and your phones will ring off the hook. I know. As public editor at the Virginian-Pilot, Norfolk, I hear from readers daily. Recently, 35 of them threatened to send us to puzzle purgatory because we messed up clues to a Monday morning crossword puzzle. Puzzles are important to readers and thus to newspapers. If you don't believe me, check out the syndicates ? most if not all offer a daily and weekend crossword puzzle. The Editor & Publisher Syndicate Section lists 83 different crossword puzzles for newspapers or magazines ? and that doesn't include other puzzles and word games. Even with my affinity for puzzling, I underestimated the interest. The lesson came home to me last year when, as features editor, I decided to drop the Cryptoquip to make more space for comics. At the last minute, I had qualms. So I set aside one of the usual daily offerings and substituted a homemade cryptogram that looked like the real McCoy. In cryptocode, I asked readers whether they cared about keeping the puzzle and provided an audiotex phone number for them to call. I expected 20, maybe 30 calls. There were more than 2,000. The message was loud and clear.