Stuart and Matty Luckett of Oxon Hill are more than a little irate with the IRS.

The Lucketts, who like to be organized and early with their tax preparations, mailed their return to the Internal Revenue Service on Feb. 4.

"We thought we'd get a head start, ha, ha," said Matty Luckett, 35, a supervisor of clerical workers at a legal firm.

Almost four months later, the Lucketts are still waiting for their $3,200 refund.

"We just knew that money was coming any day," Matty Luckett said yesterday, "and so we did a lot of home improvements and now we're in debt because we took out a loan. This is the most frustrating thing . . . ."

The IRS, reeling from one of its most troubled, oft-criticized and hectic years, has its own deadline today when refund checks are required to be issued.

Yet about 40,000 households in Maryland and 10,000 in the District have not received their refunds, said Dom La Ponzina, an IRS spokesman in Baltimore.

Residents of Maryland, the District of Columbia, Delaware and Pennsylvania are served by the IRS's Philadelphia service center, which has been the most trouble-prone of the 10 regional centers.

The number of Virginia residents still awaiting refund checks was not available yesterday, a spokeswoman at the Richmond district office said.

Virginia returns are processed at the service center in Memphis, which has had fewer problems than Philadelphia.

Any refund check not dated May 30 -- which concludes the 45-day period the law provides for the processing of refunds filed by the April 15 deadline -- will receive 13 percent interest compounded daily from that date.

For example, a $1,500 refund would receive an additional $24.77 in interest for the first 46 days, said IRS spokesman Wilson Fadely. After that, 24 cents would be added daily.

Overall, the IRS received about 100 million returns this year, of which about 70 million taxpayers were eligible for refunds.

IRS officials say they don't know how many taxpayers will end up getting their checks with interest.

But because of several factors -- including well-publicized delays and other problems caused by its new computer system -- the agency expects to dole out considerably more than the $209 million paid in interest last year.

Although many people will eventually get their checks without further paper work, about 1 1/2 million nationwide will have to file duplicate returns -- twice the number who had to refile last year. In IRS vernacular, their original returns are "unpostable."

"Their returns were entered in to our computers," said IRS spokesman Ernest Acosta, "but because of program glitches and unfamiliarity with the computers, the returns can't be processed . There are some cases where the data was erased accidentally. We still have the actual paper documents, but they would be too time-consuming to find, so we'll ask for the duplicates."

Acosta said most of those returns were filed early, in January and February, when IRS employes were just starting to use their new $103 million computer system.

The IRS discourages people from refiling, however, until 16 weeks have passed since mailing their original returns and then only after checking with the IRS.

Their refund may simply be delayed and not missing; having two returns in the computer system could further complicate the problem, La Ponzina said.

The continued waiting is not easy for people who have been counting on their refund checks. Nor has it been easy on tax preparers.

"I've never had this problem before," said James Forquer, a Lanham accountant. "I've never had clients call me up and say, 'Where is my refund?' I've had clients get penalty notices who don't deserve them . . . . I'm in the position of having to try and unscrew the IRS's screw-ups and that's bad."

Other area accountants have had similar problems.

"The computer will spit out notices saying there's been no payment," said Charles Attiliis of Merritt De La Mater Associates in Falls Church.

"Yet my client has copies of the canceled check. The end result is a lot of dead time, a lot of man-hours tracking things down. I can't charge my clients for it -- it's not their fault -- and I sure can't charge the IRS."

"I have people calling me every day who can't get through to the IRS," said Derrick Washington of Professional Tax Service in Southeast Washington.

"Seems like when you owe them, they're on you like a duck on a June bug."

In Silver Spring, Dorothy Faulconer is tired of hearing her friends talk about the things they've bought with their refund checks.

After all, Faulconer, who is due to receive $675, mailed her return on Jan. 24, while her friends lagged until March and April.

"I'm disgusted," said Faulconer, 74. "I learned how to add, subtract, multiply and divide when I was young. They should throw out the computers and let people use their heads for a change."