I've run into a problem hooking this box up to Zenith tvs. I can't seem to get the setup for screen size and resolution right. These are widescreen HD tvs and when changing between HD channels and regular channels I'm getting gray bars. Sometimes the gray bars are on the side of the regular channels, and then I change the setting and those channels are fine but there are top and bottom gray bars on the HD channels. Any help would be appreciated because this problem is giving me a headache.