It sounds to me like the remote is working perfectly and that there may be an issue with the specific Telnet cable/satellite box preventing your Slingbox to receive that signal. There is something we can give a try though, if the Slingbox is causing this issue you can try a simple hard reset of the Slingbox and run through the setup again.
Here are a couple links that can help you out with this process:
If you try this and see no results the best possible solution would be to contact your Cable/Satellite Provider to see if there possibly is a setting in the box that would prevent the second output from receiving that signal, or if possibly the box is defective.
If you have any other questions, feel free to respond or give us a call at 1-877-467-5464. We are open seven days a week, 10:00am to 10:00pm EST.
The Sling Media Moderation Team