PHASE I: Patients receive sorafenib* orally (PO) twice daily (BID) on days 1-21, gemcitabine intravenously (IV) over 30 minutes on days 1 and 8, and capecitabine PO BID on days 1-14. Treatment repeats every 21 days for at least 3 courses in the absence of unacceptable toxicity or disease progression.