It seems that ever since you switched to your new cable service provider you are no longer able to get your Slingbox AV up and running.
Even though you have applied some troubleshooting steps, I recommend you to reset your Slingbox as the first step. The following link will provide you with the instructions:
Once you reset the Slingbox, you will be able to run the Setup Assistant for Internet Viewing. Although you own the Slingbox AV and the instructions belong to the Slingbox SOLO, this link will provide you with all the details about this specific process:
The following links will provide you with some steps to follow in order to check if the IR Blasters are working in a proper way or not:
Make sure to follow all these indications and let us know how it works for you.