RATIONALE: Drugs used in chemotherapy, such as gemcitabine and docetaxel, work in different ways to stop the growth of tumor cells, either by killing the cells or by stopping them from dividing. Giving more than one drug (combination chemotherapy) may kill more tumor cells. It is not yet known whether giving gemcitabine together with docetaxel is more effective than giving gemcitabine alone as second-line therapy in treating uterine or soft tissue leiomyosarcoma.