Along the inner offices of Mayor Marion Barry's top-floor complex at the District Building, most staff members are known by the signs outside their doors.

At one door, Tina Smith, a longtime aide to the mayor, is identified as the director of special services. Dwight S. Cropp is secretary of the District of Columbia, acting. Next to Sallie Melendez, the title line is blank.

The blank spot represents one of what many Barry aides say are several personnel problems or staff arrangements that are hurting morale among the mayor's closest aides. The problems raise questions about Barry's use of his staff, what he pays them and how his personnel practices may hurt him publicly, the aides say.

According to officials, two men -- Clifton B. Smith Jr., a city ombudsman, and David E. Rivers -- are each being paid the maximum salary of $69,556 for the position of secretary of the District, but neither holds that job.

Audrey Rowe, a former commissioner of social services in the Department of Human Services, now works for the mayor as a special assistant for human resources, where she is credited with doing substantive work, but her salary of $69,556 is paid out of the budget for the human services agency, officials said. Rowe is one of 14 aides who work for the mayor but are paid indirectly by another agency.

Barry administration officials, though, say it was the unexpected hiring of Melendez, a former public relations specialist from Oakland who joined Barry's staff Oct. 1, that has heightened concerns about Barry's personnel decisions and caused a slump in morale.

Melendez is being paid $63,185 -- substantially more than many longtime, experienced aides to the mayor -- although she has not yet been assigned regular duties. Government sources said several officials have questioned Melendez's qualifications.

Melendez declined to comment yesterday and referred questions to Barry.

Asked about Melendez yesterday, Barry, in an extensive telephone interview, said, "She's a good brain, she's a good team player and knows how to get the job done. I just finished having lunch with her to give her some ideas on arts and humanities because Effi's {the mayor's wife} interested in that."

Barry said he will announce at a Cabinet meeting today that Melendez, one of six special assistants, will be assigned as the mayor's liaison to about a dozen offices and agencies, including arts and humanities, employment services, cable television, the Washington Convention Center, communications, the mayor's press secretary and business and economic development.

Barry said Melendez, who previously worked for the mayor of Oakland and a private development firm there, "came highly recommended" from several people in Oakland, including city council member Leo Bazile, a longtime friend of Barry's.

Barry said he was angry that any officials in his administration would speak about his staff without identifying themselves. "Those people who won't give their names don't represent my point of view and they shouldn't be working for me," he said. "I don't believe they exist in my administration."

It is the second time in two months that members of Barry's staff have questioned his handling of his office.

In mid-September, aides who declined to be identified complained that Barry was not paying attention to his job. In recent weeks, however, the mayor has gotten back on track, they say, and has focused on a variety of initiatives to show he is working harder. The personnel question, one official said, could undermine the positive work Barry has done.

Barry, who has a number of political friends on the West Coast, said he hired Melendez, whom he has known for three to four years, after interviewing a half dozen people for one of two open positions on the mayor's staff.

One official familiar with Barry's hiring practices praised the recent hiring of Phil Watson, a longtime Washingtonian who is paid $47,397 as special assistant for financial affairs, but said the mayor and key staff members were "trying to develop a job for {Melendez} now that she is on the payroll."

Barry late yesterday told two deputy mayors -- Carol B. Thompson and Thomas M. Downs -- to call The Washington Post to say they support Melendez.