 Patients receive cisplatin IV over 1 hour on day 1 and irinotecan IV over 60 minutes on days 1, 8, and 15. Treatment repeats every 28 days for a maximum of 4 courses. Patients also receive oral imatinib mesylate daily continually for one week prior to, during, and after chemotherapy in the absence of disease progression or unacceptable toxicity. 