One in four taxpayers -- about 30 million people or more -- are dissatisfied with the way the Internal Revenue Service has handled their income tax returns this year, according to a Washington Post-ABC News public opinion poll.

Discontent is highest in the East, where 30 percent are critical.

Criticism of the IRS has been fueled by delays in the processing of tax returns and a variety of other problems, including computer breakdowns and IRS errors.

Problems have been particularly severe at the Philadephia Service Center, where returns from the District and Maryland are sent.

The survey found that 41 percent of those who filed for a refund had not received one by the period from May 9 to May 13, when the poll was conducted.

That figure represents perhaps 40 million taxpayers and includes 5 percent of filers who said they heard back from the IRS but had not received a refund.

Seventeen percent of those who filed for a return before March said they had not received one, meaning they had waited at least 10 weeks without payment. For people who filed in March, the proportion not receiving a refund was 38 percent; for those who filed in April, it was 85 percent.

Among taxpayers who did get their refund, about one in five had to wait four weeks or less; about four in 10 waited five to seven weeks; two in 10 waited eight to nine weeks, and one in seven waited 10 weeks or longer.

An IRS spokesman said the Post-ABC poll figures on refund delays appeared to be consistent with IRS information.

If all outstanding refund requests were honored by the IRS today, the average wait for all people seeking refunds would amount to 10 weeks, according to the poll.

The IRS is now 4 percent behind last year's pace in processing returns compared with 60 percent behind in January, the spokesman said.

But the Philadelphia Service Center is lagging 17 percent behind last year's pace.

The poll suggested that refunds have taken somewhat longer in the East than in other regions.

As might be expected, those who have waited the longest for refunds are more unhappy with the way the IRS has handled their return, as are those who have not yet received their refund. People who said they owed money to the IRS on their income tax return -- 22 percent of those who filed -- also are less satisfied.

Thirty-five percent of those interviewed said they filed their returns in February or earlier, 17 percent filed in March, 34 percent filed in April, 2 percent received an extension and 8 percent said they did not file; 4 percent did not recall when they filed.

Predictably, early filers were much more likely to claim a refund on their federal income tax return.

In all, 73 percent in the survey said they were satisfied with the IRS's handling of their return, 24 percent said they were dissatisfied and 3 percent offered no opinion.

Comparisons for past years are not available, as the Post was unable to find any similar question asked in a survey before 1985.

Figures were based on telephone interviews with 1,503 adults in the continental United States. The poll had a 3-percentage-point margin of sampling error.