I had similar issues when running multiple sources for iCam until I properly set up port forwarding. Do you have uPNP enabled in your router and in icamsource? If so, have you rebooted the router after enabling uPNP? Or if you prefer not to enable uPNP, you can manually forward the necessary ports (see sticky at/near top of this forum). Manual port forwarding would require that your computers (or IP cameras if applicable) have static IP's assigned to them. But all of this is just a guess...your post is lacking some details, such as: Do you encounter any error messages? What version of icamsource are you running? Do you encounter the problem when connected to your network with your iPhone, or only when connecting from 3g or some other network away from home? Are you using the exact same username/password in icamsource on both computers?
If my tip doesn't help, write back and answer those questions...then I'm sure the SKJM guys can help you out.
