Thank you for posting the in the forums! I'm sorry to hear you are having trouble connecting to your Slingbox via SlingPlayer for Android Tablets. When it gives you that message, it means that your phone cannot verify that you paid for the application. I would recommend uninstalling/reinstalling the application. As long as you are logged in to the same Google Play account (Gmail account), you will not have to pay for the application again. If the issue persists, you will need to contact Google Play support and they should be able to resolve the issue for you.
Hope this helps!
The Sling Moderation Team