NBA referees' competency has always been criticized. After three high-profile negative stories in the last three months, the questions have shifted to their credibility.

One official was suspended after allegedly challenging an NBA superstar to a fight, and an academic report suggested a bias by referees against players of the opposite race.

Now, most damaging, a referee's at the center of a potential point-shaving scandal.

With the FBI investigating Tim Donaghy for allegedly betting on games that he officiated, confidence in the guys blowing the whistles may never have been lower.

Lamell McMorris, leader of the referees' union, said he recognizes the perception of officials has been damaged.

"We are going to work hard to restore the public's trust in the integrity of the officials in the NBA," he said. "We're going to do our part to gain and regain the public trust and confidence and to make sure that this is not the final word regarding how referees are defined in the public eye."

Last year, commissioner David Stern said the NBA had "the best officials, the best-monitored officials, the best-developed officials in all of sports."

But now it's their judgment, not their performance, that needs defending.

Stern plans to do just that at a press conference next week. The NBA and the referees' union want to make sure Donaghy, who McMorris confirmed has resigned, is the one taking the heat, not his co-workers.

"Bad apples exist in every barrel," McMorris said. "I've never seen a barrel of apples, grapes, anything, and all of them were in the greatest shape and the most beautiful."

But Donaghy's mess isn't the league's only trouble involving its officials.

Stern had to suspend Joey Crawford, who had worked more postseason games than any active ref, after Crawford ejected San Antonio's Tim Duncan from a game in April. Duncan, who was on the bench laughing when hit with his second technical foul, later said Crawford challenged him to a fight.

Then came details from a study done by Justin Wolfers, an assistant professor of business and public policy at Penn's Wharton School, who found white referees called fouls at a greater rate against black players than against white players.

But a defense came yesterday from, of all people, Dallas owner Mark Cuban.

Cuban long has been critical of referees, racking up more than $1.4 million in fines, mostly for comments about the officiating. That included a $250,000 hit after Game 5 of the 2006 NBA finals, when Miami had a 49-25 advantage in free throws attempted, with Dwyane Wade taking as many as the whole Dallas team.

But in a blog entry titled "Calamity as Catalyst - My Vote of Confidence in the NBA", Cuban wrote: "The NBA took a hit today. Behind that hit is a catalyst and opportunity for significant change that could make the NBA stronger than it ever has been. It's a chance to proactively put in place people, processes and transparency that will forever silence those who will question the NBA's integrity."

Cuban declined to discuss what any of those might be, simply saying: "The NBA is fine and will be fine. In fact it will continue to get better" in an e-mail.

It's not clear what affect, if any, the Donaghy allegations will have on the relationship between players and officials, which was contentious early last season after the league ordered officials to call more technical fouls. The players' association even filed an unfair labor practice charge with the National Labor Relations Board against the NBA over the crackdown on player complaints.

Still, many officials are highly regarded among players because of their work on the floor. And McMorris expects it to remain that way.

"I think individuals and the public needs to understand that these individuals go out and work hard, they officiate the games to the highest standards and they are men and women of extreme integrity," McMorris said.