What happened th the tv listings page?
What do you see when you press GUIDE on the remote? If all times show NO DATA, unplug your DVR for 30 seconds and replug it. That's what Cox told me to do when i had that problem.
If you can't see the guide at all, call Cox phone support to get it working again. Then can access it remotely. The forum moderators might not be here until Tuesday if they get the Monday holiday off.