Drugs used in chemotherapy, such as arsenic trioxide and pamidronate, work in different ways to stop the growth of cancer cells, either by killing the cells or by stopping them from dividing. Arsenic trioxide and pamidronate may also stop the growth of cancer cells by blocking some of the enzymes needed for cell growth. Pamidronate may also stop the growth of cancer cells by blocking blood flow to the cancer. Giving arsenic trioxide together with pamidronate may kill more cancer cells. This phase I trial is studying the side effects and best dose of arsenic trioxide and pamidronate in treating patients with advanced solid tumors or multiple myeloma