 Patients receive irinotecan IV over 30 minutes followed by 17-N-allylamino-17-demethoxygeldanamycin 17-AAG IV over 2 hours on days 1 and 8. Treatment repeats every 21 days for at least 2 courses in the absence of disease progression or unacceptable toxicity. Patients achieving stable or improved disease after course 2 may receive additional courses of treatment. 