||Key inflation measure soars on huge jump in energy prices, but other prices nearly flat. Consumer prices rose at the fastest pace in more than 25 years last month, spurred by a surge in energy prices to record highs after Hurricane Katrina. At the same time, though, a closely watched measure of so-called core inflation, excluding volatile food and energy prices, showed surprisingly little price pressure in September. The Consumer Price Index, the government's main inflation gauge, jumped 1.2 percent in September after rising 0.5 percent in August, the Labor Department reported. The department said energy costs were responsible for 90 percent of the rise. Record gasoline prices in September after Katrina sent energy prices soaring 12 percent in the month.