It seems that you are having some issues with the SlingPlayer for iPhone application since once you turn on the connection to your Slingbox, an error message pops-up and cuts the connection.
We are sorry about this situation, however, this error message seems to be related to your iPhone Mobile device and not to the Slingbox. In all case, I recommend you to remove the application and install it one more time. If you do not know how to, just check this link:
Hope this helps!