 REGIMEN B VACVI TEMSIROLIMUS: Patients receive vincristine sulfate IV over 1 minute on day 1 of weeks 1-13, 16, 17, 19, 20, 22-26, 28, 31-34, 37, 38, and 40, dactinomycin IV over 1-5 minutes on day 1 of weeks 1, 7, 13, 22, 28, 34, and 40, cyclophosphamide IV over 60 minutes on day 1 of weeks 1, 7, 13, 22, 28, 34, and 40, irinotecan hydrochloride IV over 90 minutes on days 1-5 of weeks 4, 10, 16, 19, 25, 31, and 37 and temsirolimus IV over 30-60 minutes on day 1 of weeks 1-12 and 21-42. Patients also undergo RT as in Regimen I. Treatment continues in the absence of disease progression or unacceptable toxicity. 