I use cablevision and have i/o digital cable. I am using a explorer 4200hd cable box but am unable to receive broadcasts from certain channels which I know are available to me and have seen in the past. I have tried a reboot of the box but to no avail. I can receive most of the channels but some of them give a message channel not available at this time. I am about to call the cable company but was wondering if anyone has ideas I can try prior to my making the phone call. Thank you.