It seems that you are having some issues in order to configure your Slingbox SOLO for Internet Viewing on your two-router network.
If you have any kind of conflict regarding the IP addresses in use, I recommend you to reset the Slingbox and run the Setup Assistant for Internet Viewing through the Manual Configuration. If it is not clear enough, you can check the following links.
Manual Setup for the Slingbox SOLO
I also recommend you to check the following link, since you have two routers on your home network.