A day after the District acknowledged that its parking meters at times do not give motorists proper credit for their coins, several drivers called the city to protest tickets they say they received because the meters malfunctioned.

Also yesterday, D.C. Council member Carol Schwartz (R-At Large), chairman of the panel's Public Works Committee, questioned why parking officials did not previously disclose the meter flaws--despite two inquiries by the council this spring.

"I don't want to see the city take people's money without giving them the allotted time on the meter," said Schwartz, who noted that she has had her own problems with parking meter coins failing to register.

The trouble with the District's 15,000 new parking meters is similar to those experienced in Portland, Ore., Los Angeles and Berkeley, Calif., officials in those cities said yesterday. They and the District use the same model meter, manufactured by Duncan Industries Inc., of Harrison, Ark.

The computerized meter, about 150,000 of which have sold since it was introduced in 1997, is so sensitive in guarding against slugs or foreign coins that it sometimes doesn't give motorists credit for genuine U.S. coins they drop in.

"It has caused a lot of heartaches for both the parking enforcement personnel and the people who are improperly getting tickets," said Los Angeles City Council member Joel Wachs, chairman of the council's transportation committee. "There is a lot of anger and hostility out there, and for good reason. It has to get corrected."

Duncan Industries sales director Gorm Tuxen said the coin error happens in "an extremely small percentage" of the transactions. Duncan Industries has begun recalibrating the meters here and in the other cities to try to make them less sensitive to slight flaws in U.S. coins, and Tuxen said he is "absolutely, 100 percent certain" the problem will be solved within three months.

But some officials say the recalibration doesn't necessarily work. And that still leaves the question of what to do about drivers who may have been unfairly ticketed.

David R. Feltman, a Dupont Circle fund-raising consultant, said yesterday that he put 90 cents into a meter on N Street NW, but got credit for only eight minutes' worth of parking. Instead of adding more change, he put a note on his windshield to alert any ticket issuer to the problem.

When he returned to his car, he found a ticket anyway. "I was appalled," he said. "I have taken the time to write out a note and I put it in as visible of a place as I could find. Yet they still gave me a ticket."

Feltman appealed the ticket, which he got in February, but the city denied his challenge and said the meter was operating properly. After reading about the malfunctioning meters, he called the city again yesterday.

Parking officials said they had received several similar calls, although they could not provide an exact count.

Donald Schieffer, a federal government auditor from Fairfax, had his own troubles with an errant meter. When the coins he put into the meter did not register, he said, he wrote a note of explanation and left it on his car. He later saw a parking enforcement officer in the area.

"I explained to her that the meter was not working, and she said to me, 'That is not my problem,' " Schieffer said. He decided to move his car before he got a ticket.

In Portland, officials have been voiding ticket fines when they can document the meter flaw--which they say is turning up across the city.

"If you have the meters, you have the problem," said Keith Ehrensing, a Portland transportation official.

The City Council in Los Angeles is scheduled to consider legislation next week that would establish an automatic refund program for tickets given because of a flawed meter. A study completed there this month found that even when the meters have been "retrofitted," they are sometimes failing to register coins or jamming.

One official involved in the District's meter program, who asked not to be named, said that some District meters that have been recalibrated also are still having the same coin problem.

Schwartz said she is hesitant to push for a refund or forgiveness program because it is hard to prove that the meters are at fault. "How could you verify it?" she asked.

The city is checking all reports of malfunctioning meters and is committed to resolving the problem, regardless of how isolated it might be, said Gwen Mitchell, head of the District's Parking Services Administration.

"I don't want anyone to lose a nickel," she said. "If it happens to one individual, it is a concern to me."

CAPTION: Member Carol Schwartz said the D.C. Council wasn't told about the meters.