Thanks for using the forums. Sorry to hear you are having issues getting the Slingbox to work over the internet. When you get a new router, you would need to reset the Slingbox to get it to recognize the new router and set it back up using the website setup.slingbox.com. In order to set up the internet viewing for the PRO-HD, you would use ports 5001, 5002, 8080, or 443. You can also follow a user guide on the website www.portforward.com for step by step directions on how to set up the Slingbox for port forwarding.
Hope this helps,
Sling Media Moderation Team