Please check to make sure the iCamSource window isn't hidden. If it is, there will be a small iCamSource icon in the Menubar. The icon is a small version of the iCam icon (camera lens). From this icon, you can stop, start, or quit iCamSource. If you select "Preferences" it will display the iCamSource window.
Do you see the iCamSource icon in the menubar or system tray?