Russell Crandell and Naoko Ishibe are two of the area's fastest runners. But after they won their respective divisions in the Jingle Bell Run for Arthritis yesterday in really fast times, they said they thought something was wrong.

They were right.

The 10K course was incorrectly marked and about one-third of a mile short of the regulation 6.21 miles. So when Crandell finished in exactly 30 minutes and Ishibe in 34:00, both knew their times were faster than they should have been.

"I figured I was running around a sub-31 pace," Crandell said. "When I saw I finished in 30 flat, I figured the course was short."

Said Ishibe: "It was a great day to run. I was going to submit my time as a personal best and now I can't do that. It's very disappointing."

More than 3,700 people ran the 10K and accompanying 5K races, each of which traversed a flat course in downtown Washington. Some runners dressed as Santa Claus, angels, reindeer or Christmas trees. Many ran with bells on their wrists and feet.

But Crandell and Eron Ferriera were all business. They shared the lead after a 4:59 first mile; Crandell pulled away about a half-mile later. Ferriera finished second in 31:33, just ahead of Eric Desaultes, who was third in 31:35.

Ishibe led throughout the women's race and finished 49 seconds ahead of Rhonda Gouge. Kirsten Black placed a distant third in 36:36. It was Ishibe's third victory in six weeks. She won six of the seven times she raced last summer.

"I guess I've been running pretty well this season," Ishibe said. "I was only going to run the 5K today but the conditions were ideal and I had read it was going to be a fast course. I just wish it had been right."

Notes: Steve Nearman won the 5K race in 17:42; Sushilda Nanda won the women's 5K in 21:14. There were no problems with the length of the 5K course, according to race director Kathy Freedman.