Drugs used in chemotherapy use different ways to stop cancer cells from dividing so they stop growing or die. Imatinib mesylate may stop the growth of cancer cells by blocking the enzymes necessary for cancer cell growth. Combining more than one chemotherapy drug with imatinib mesylate may kill more cancer cells. Randomized phase II trial to study the effectiveness of combination chemotherapy and imatinib mesylate in treating children who have relapsed acute lymphoblastic leukemia.