The New Job Is in the Details - Five danger zones where small slip-ups could damage your chances

Here's an important New Year's resolution for job hunters: Sweat the small stuff.

Minor missteps can derail your search. With U.S. joblessness still rampant, numerous hiring managers are knocking applicants out of the running over the slightest mistake.

That's what sporting-goods sales executive Daniel Obergfell did while seeking a marketing manager last winter. He rejected one contender for mispronouncing his surname four times—after correcting her thrice. (His last name actually is pronounced "Oberfell," with a silent "g.") She was among 40 people he interviewed for the $80,000 post, which attracted more than 400 prospects from one online listing.

"Your nerves cause you to do things you would not normally do when you must vie against many people for a job," Mr. Obergfell says. Despite such sentiments, he explains, he "couldn't get past" his disappointment over the woman's failure to pronounce his name right. "Given she never really got it right—even after being corrected, told me it was probably started with nervousness, but the issue more than likely ran deeper than that," he says.

Small interview errors are becoming more common. "Compared with two years ago, about 20% more candidates interviewed by our clients are not getting offers because of gaffes made due to their high anxiety," says Dave Campeas, president and chief executive officer of PrincetonOne, an executive-search firm in Skillman, N.J.

The incidence of nervous job candidates has doubled since 2006, causing some to commit careless mistakes that "ruin their chances because they didn't present themselves well," says David Mezzapelle, director of marketing and development for Goliath Jobs Inc. in Stamford, Conn.

He bases his estimate on several thousand calls from job seekers, who use a free phone service provided by his firm's two employment Web sites. The 39-person concern grew from 28 staffers a year ago.

The best solution? Prepare better for interviews. Added legwork should include extensive role playing, thorough homework about a possible employer's culture and an empathetic sense of how your skills match its needs. "Turn your dial up on sensitivity," suggests Gerard Roche, senior chairman of recruiters Heidrick & Struggles International Inc. "The little stuff counts."

Here are five danger zones where small slip-ups could damage your chances: