If, when you launch the iCamSource application, you are unable to see the iCam Preferences window to change your login and password but you do see your webcam status light turn on, then you have likely checked the Auto Start checkbox in the iCamSource so that when the application starts the iCamSource Preferences window is hidden and the only way to access the application would be to click on the icon in the menu bar.
(You can always reset all of your iCamSource settings by deleting the com.skjm.icamsource.plist file in your ~/Library/Preferences folder to reset the iCamSource settings as mentioned in my other post:
http://skjm.com/forum/index.php?topic=582.msg12900#msg12900)
If you cannot see the icon in the menu bar when the iCamSource is running then you may have a "full" menu bar with a lot of other icons and items in it at a low screen resolution that are moving the iCamSource icon out of view. If you could take a screenshot of your screen when the iCamSource is running and send it to support@skjm.com we can see if that may be the issue:
http://guides.macrumors.com/Taking_Screenshots_in_Mac_OS_XThe other possibility (if you do not see the icon in the menu bar and you do not see your webcam status light turn on) is that the iCamSource is not actually running. Another way to check if the iCamSource is actually running is to look for the iCamSource in the Applications > Utilities > Activity Monitor application. If it is in the list, then it is running. If it's not running, then you shouldn't see the icon in the menu bar.