OBJECTIVES: I. Determine the toxicity of dimethylxanthenone acetic acid (DMXAA) in patients with solid tumors. II. Establish a maximum tolerated dose for this drug in these patients. III. Determine the pharmacokinetics of DMXAA in these patients. IV. Determine the effect of this regimen on coagulation parameters, TNF and other cytokine production, nitric oxide, and serotonin production in these patients. V. Assess the efficacy of this drug in this patient population. VI. Determine the effect of this drug on tumor vasculature by evaluating any changes apparent on MRI scans in these patients.