It seems that you are having some issues in order to get the connection to your Slingbox SOLO.
According to the provided information, it seems that the issue is related to the computer you are using and not the Slingbox, otherwise you would not be able to get the connection on your iPhone.
With this in mind, I encourage you to check the following link in order to check the requirements for the Slingbox SOLO:
Well that may be an acceptable answer if I was only having the problem with one computer. I have tried two laptops running different OS and one desktop and have the same problem. I run my own domain, DHCP and DNS/DNS-relay and Cisco IOS firewall. All other apps run flawlessly and the old singbox works just fine. There is something about this Solo that is sigificanly different than the clasic that is preventing it from connecting on the internal LAN. The app on the iphone must be streamlined or not using some port or ?? that is allowing it to connect but not other devices. If I had the time...I would sniff it and find out....but I'm just not in the mood.