MARBLEHEAD – School Committee members were smiling last week to hear that Marblehead High increased the number of students in Advanced Placement classes and the number of high scores in College Board Advanced Placement exams.But before the meeting ended they found themselves on the verge of arguing with Marblehead High Principal Kenneth Weinstein and new Assistant Principal Debra Heaton over the scheduling of classes at the school, including advanced placement classes.In his annual class size report Weinstein said there were 29 high school classes with less than 12 students enrolled and 35 classes with more than 24 students.?This is largely a scheduling problem, not a staffing problem,” Weinstein said. “The problem is that we have available staff with no rooms to teach in.” He added that the high school relies “too heavily on computer scheduling.”Committee member Thomas Connolly said Weinstein?s report countered local rumors that the high school is too large and the School Committee should publicize those facts.Committee member Dick Nohelty said, “This is the fourth year with the same problem.”He reiterated a criticism from last year that there seem to be too many study halls.?Many students want study halls to get their homework done,” Heaton said. She said, however, that “mistakes were made last year in the scheduling process, before I got here.”Weinstein said he and Heaton “make every effort to get every kid what he needs to graduate.” When he suggested a study of class scheduling, however, Nohelty became impatient. “That doesn?t help those kids,” he said.Superintendent of Schools Greg Maass intervened. “Let?s accept the history,” he said. “We didn?t do very well with scheduling last year, but now Debra Heaton owns scheduling and she will be working to make this better.”