Most likely the Slingbox itself is still using the IP configuration from the old router.
I recommend in performing a factory reset of the Slingbox (http://support.slingmedia.com/get/KB-1000038)
and here's some information that might help you reconfigure port forwarding. (http://portforward.com/english/routers/port_forwarding/Apple/AirPortExtreme/SlingBox.htm)
Nah, deleting the program does nothing for the setup configuration of the Slingbox.
The Slingplayer program cannot access the Slingbox if it does not have a valid network configuration for your network.
Check the network light of the Slingbox, if it is not lit then it didn't receive a valid IP configuration from your router's DHCP server.
Maybe check the router's list for active DHCP leases, see if it gave one to your Slingbox
I am having this problem too. I remove the application and delete the directory Sling Media, but it still will not let me run through the setup again.
Resetting the box has nothing to do with the software on my computer, although I can just use another computer or refomat my hard drive, but that seems excessive.
I'm trying to fix a different problem and think reinstalling will help. The program just doens't think I can connect to the internet due to some ISP filterng, but they offer very poor error messages. They should fix the error messages. "Cannot connect to the Internet" doesn't tell the ISP firewall administrator much information !!
These are some of the sites that Slingplayer and Slingbox will use for it services.
And these are some of the port numbers it will use, 3490, 80, 443, 3074, 3724, 5680
Usually, you wouldn't need to make firewall changes unless you're using a enterprise class firewall. Since these connections are orginate from within the subnet a private network, standard NAT functionality allow it.
If you're having issues where the Slingplayer respondes with "Cannot connect to the Internet" it could also be due to misdirect ISP issues.