It seems that you are having some issues with your Slingbox since it got frozen and you cannot get the connection whether you use the SlingPlayer Mobile application or your computer.
Since the issue affects also the streaming signal to your computer, I recommend you to reset your Slingbox and run the Setup Assistant for Internet Viewing. The following link will provide you with further details:
Once you've applied these troubleshooting steps, you can also uninstall and reinstall the SlingPlayer for iPhone. The following link will provide you with all the related information:
Hope this helps!