Temozolomide is given by mouth one hour prior to each daily irinotecan dose days 1-5 of each cycle. 100 mg/m2/day. Irinotecan is given IV in dose escalation (minimum of 3 and up to 6 patients per cohort) starting at 15 mg/m2/day daily for 5 days for 2 weeks. Vincristin is given IV 1.5 mg/m2/dose (max dose 2mg) days 1 and 8 of each cycle. Vantin is given 10 mg/kg/day divided in 2 oral doses (max dose 400 mg/day) started 48 hours prior to the start of each treatment cycle and continued for 48 hours after last irinotecan dose. Cycle repeated every 28 days.