Officials at an elementary school rocked by teacher sex abuse claims are investigating yet another allegation of misconduct, this one involving a teacher's aide accused of sending love letters to an 11-year-old boy. The mother of the fourth-grader told the Los Angeles Times that the aide, a woman who appeared to be in her 50s, sent at least three letters to her son in 2009, including one that read: "when you get close to me, even if you give me the chills I like that. Don't tell nobody about this!" The allegations come as school district administrators move to replace the entire staff at Miramonte…