Occasionally when I view my VCR (VHS) through the 811's video inputs for an extended period of time, usually 30 or more minutes, when I return to regular satellite programming, the screen remains blank. The transparent guide is viable but nothing else. Even OTA doesn't come in. The menus are visable. When I return to 000 (back video inputs) I can still see the VCR. I've ran the switch test, turn the 811 off and on. Nothing. The last resort was to unplug the receiver. This worked. I hope this isn't a duplicate post. Any ideas what causing this?