A few questions for you.
If you are home and use your home remote, can you bring up your recordings on your TV or does this freeze as well?
If the recordings freeze as well, this will be an issue to contact your cable provider on.
If you are able to use all the functions on the home remote with no problems, I recommend to uninstall and reinstall the application. As long as you are still logged into the same Apple ID as you purchased the SlingPlayer for iPad the first time, you can install the application for free.
Awaiting your response!!!
Sling Media Moderation Team