WASHINGTON (AP) - Public anxiety about the Y2K computer bug has eased in the past six months, says an Associated Press poll, but a majority of Americans expect minor problems and a third say they plan to stock up on supplies. "It's stupidity not to at least take precautions," said  48-year-old Diana Chavez of Bernelillo, N.M., near Albuquerque. The poll, conducted for the AP by ICR of Media, Pa., said that 70% of Americans expect minor problems, 23% expect no problems and only 5% expect major problems. The number of people who expect major problems dropped from 11% in a July poll on the same topic. The percentage of people who think Y2K problems will last more than two weeks dropped by half, from 32% to 16%, and the number who think the problems will be confined to less than a few days has increased from 22%.