54 set up last week and experiencing two problems. At least once a day when I switch channels or go to a recording the scree goes black, then green with a lost signal message then to a screen of white snow. Periodically the screen will go black again then back to all snow. Pushing different buttons does not help. If I power off then back on all is fine again. Problem two is momentary frame freeze including audio and video. Live as well as recorded material. Signal strength is excellentl.