I see you're having some trouble connecting to your Slingbox using the 3G network of your iPhone. Have a look at these pages, they'll help you verify that everything is set up properly:
If you still have the same issue after confirming that the Internet Viewing is set up correctly, try adding the Slingbox using a Direct Connection on the iPhone, that should fix the issue.
I hope that helps!
The problem is Slingplayer for the iPhone won't switch to the 3G network after connecting to WiFi. It stays stuck in the WiFi mode. To get it working outside of your home wireless network, double click the home button on your iPhone. That will bring up a list of icons of currently running applications. Locate the Slingplayer icon. Tap and hold for several seconds until a red minus (-) sign appears. Tap on the minus sign to kill off the Slingplayer app. Click the home button again to exit app management. Now start the Slingplayer app again as normal. It will now connect via 3G.