HUDSON, N.H. -- A key detail in a story told by Democratic presidential candidate John Kerry is being questioned. The Massachusetts senator has repeatedly talked about a New Hampshire woman who was undergoing chemotherapy for breast cancer. Kerry says she continued working out of fear of losing her health insurance, because her husband was unemployed.In television ads, e-mails and speeches, Kerry has used the plight of Mary Ann and John Knowles to criticize the Bush administration's health care policies. But the Knowles' own account differs in one key detail. John Knowles told the New Hampshire Sunday News that Mary Ann...