OUTLINE: This is a dose escalation study of GEM 231 and docetaxel. Patients receive docetaxel IV over 1 hour on day 1, immediately followed by GEM 231 IV over 2 hours on days 1, 4, 8, and 11. Treatment continues every 3 weeks in the absence of disease progression or unacceptable toxicity. Cohorts of 3-6 patients are treated with escalating doses of GEM 231 and docetaxel until the maximum tolerated dose (MTD) is determined. The MTD is defined as the dose at which no more than 2 of 6 patients experience dose limiting toxicity. Patients are followed monthly for 3 months.