 After 2 weeks of treatment you will have another biopsy of your tumor, and another functional MRI. After every 9 weeks of treatment and every 2 cycles thereafter you will have a repeat CT or MRI to evaluate your tumor. If your disease has responded to ZD6474 or stayed the same, you will go on to the second part of this study. If your disease has gotten worse or intolerable side effects occur, you will be taken off this study and your doctor will discuss treatment options with you. 