Disability-insurance seller Aflac ( AFL) saw a 20% jump in first-quarter earnings, buoyed by its Japanese division. For the quarter, earnings reached $569 million, or $1.22 a share, compared with $474 million, or 98 cents, in the year-ago period. Analysts were expecting earnings of $1.16 a share. Revenue grew 13% to $4.8 billion, boosted by a stronger yen. The company also announced a second-quarter cash dividend of 28 cents a share, which is payable on June 1 to shareholders of record at the close of business on May 20, 2009. Last week the company was downgraded by Barclays from equal-weight to underweight.