School just ain't what it used to be . . . an Iowa elementary school teacher resigned after her superiors threatened to reprimand her for letting a group of students continue a research project on controversial rapper Eminem, 28, reports the Associated Press. Administrators at the school in Tipton, Iowa, told music teacher Cassie Johnson, 24, to cancel the sixth graders' project after parents complained their child had found inappropriate material on the Internet. Johnson said she assigned different topics to the students after the parents' complaint but then allowed them to continue working on the Eminem assignment after learning that students in another class were allowed to give a presentation on the same subject. Johnson argued that the presentation didn't have any references to Eminem's lyrics, which contain obscenities and references to violence. Principal Brian Krob declined to discuss details of the incident.