DISEASE CHARACTERISTICS:

• Histologically confirmed solid tumor

• No untreated brain metastases

  • Patients with stable brain disease (no concurrent corticosteroids) ≥ 4 weeks after completion of appropriate therapy are eligible

PATIENT CHARACTERISTICS:

• ECOG performance status ≤ 2 OR Karnofsky performance status 60-100%
• Life expectancy > 12 weeks
• WBC ≥ 3,000/mm^3
• Absolute neutrophil count ≥ 1,500/mm^3
• Platelet count ≥ 100,000/mm^3
• Bilirubin normal
• AST/ALT ≤ 2.5 times upper limit of normal
• Creatinine within normal institutional limits OR creatinine clearance ≥ 60 mL/min
• Not pregnant or nursing
• Negative pregnancy test
• Fertile patients must use effective double barrier contraception for at least 1 week before, during, and for at least 2 weeks after study participation
• No peripheral neuropathy > grade 1
• No history of allergic reactions to paclitaxel
• No history of allergic reactions attributed to compounds of similar chemical or biologic composition to study drugs
• No inability to take oral medications on a continuous basis
• No psychiatric illness or social situation that would limit compliance with this study
• No ongoing or active infection
• No symptomatic congestive heart failure
• No unstable angina pectoris
• No cardiac arrhythmia
• No other uncontrolled illness

PRIOR CONCURRENT THERAPY:

• No more than 2 prior chemotherapy regimens for advanced/metastatic disease

  • Adjuvant chemotherapy administered ≥ 2 years prior to study entry is not considered a prior chemotherapy regimen for purposes of this study
• No prior therapy with paclitaxel
• No chemotherapy or radiotherapy within the past 3 weeks (6 weeks for nitrosoureas or mitomycin C) and recovered
• At least 4 weeks since prior valproic acid
• No other concurrent anticancer therapies or agents
• No other concurrent investigational agents
• No concurrent combination antiretroviral therapy for HIV-positive patients
• No concurrent oral contraceptives
• No concurrent prophylactic growth factors