Check finder preferences and make sure CDs, DVDs, and ipods are checked to show on the desktop. If that's okay check system profiler under ATA and see if your optical drive is listed. If it is listed check further to see if it recognizes the media you inserted. If it still won't eject try restarting and hold down the mouse button to see if it will eject. If it happens to be a mini disk you inserted into a slot load optical drive, that may need to be taken apart and removed.