Patients receive cytarabine IV over 24 hours on days 1-4 for patients under 65 years of age OR on days 1-3 for patients 65 years of age and over. Patients also receive VNP40101M IV over 15-60 minutes on day 2. Treatment repeats every 4 weeks for up to 3 courses (in patients with responding disease) in the absence of disease progression or unacceptable toxicity. Patients with a continued response may receive additional courses at the discretion of the investigator.