Temsirolimus and Valproic Acid in Treating Young Patients With Relapsed Neuroblastoma, Bone Sarcoma, or Soft Tissue Sarcoma

DISEASE CHARACTERISTICS: * Histologically confirmed malignant solid tumor at original diagnosis, including the following: * Neuroblastoma * Bone sarcomas (primary neuroectodermal tumors/ Ewing sarcoma (PNET/ES), osteosarcoma) * Soft tissue sarcomas (rhabdosarcoma and related tumors) * Histologically confirmed of relapsed disease is highly recommended but not mandatory * Measurable disease according to RECIST * Refractory or progressive disease after ≥ 1 and ≤ 4 prior chemotherapy regimens * Patients with neuroblastoma, PNET/ES, or rhabdosarcoma must have failed a cyclophosphamide/topotecan-containing regimen * Stem cell transplantation, including preparative regimen and post-transplant immunotherapy, is considered to be 1 regimen PATIENT CHARACTERISTICS: * Karnofsky performance status (PS) 50-100% (or Lansky PS 50-100%) * Life expectancy ≥ 8 weeks * ANC ≥ 750/mm\^3 * Platelet count ≥ 75,000/mm\^3 (transfusion independent) * Hemoglobin 8.0 g/dL (may receive RBC transfusions) * Patients with tumor metastatic to bone marrow are allowed to receive transfusions to maintain hemoglobin and platelet counts * Serum creatinine normal * Total bilirubin ≤ 1.5 times upper limit of normal (ULN) OR direct bilirubin \< 1.0 mg/dL (if total bilirubin \> 2.0 mg/dL) * ALT \< 5 times ULN * Negative pregnancy test * Not pregnant or nursing * Fertile patients must use effective contraception * Families must be able to give consent in English or Spanish * No allergy to H1 antihista…