DISEASE CHARACTERISTICS: Histologically or cytologically confirmed advanced and/or metastatic solid tumor refractory to standard curative therapy or for which no curative therapy exists Clinically or radiographically documented disease No tumor marker elevation as only evidence of disease No untreated brain or meningeal metastases Previously treated and stable CNS metastases allowed (i.e., no evidence of increasing disease by CT scan for at least 4 weeks) Recommended phase II dose portion of study: Previously untreated advanced and/or metastatic disease for which a cisplatin-based regimen is indicated (e.g., non-small cell lung cancer, small cell lung cancer, ovarian, or head and neck cancer) At least one measurable lesion at least 20 mm by physical exam or x-ray or at least 10 mm by spiral CT scan