I recently bought a TivoHD and had two motorola single stream cable cards installed by the cable company. After he installed them the channels all seemed to come up correctly, so i did the guided setup again as the instructions say to do and left for a while, when i came back i noticed some of the channels were blank (Black Screen). I figured maybe i needed to reset the box and they would come back. Once the box reset, the channels worked again for a short period of time. I am recieving most of the lower channels, but most if not all of the HD channels after a short time just go to blank screen on both of my cable cards. It is not always the same channels that go out from what i can tell. After numerous restarts to get the channels working and only having them go out again i am getting frustrated. I browsed some of the posts on here and a troubleshooting guide was put up by a user reguarding pairing and validation. I looked through all the steps and from what i can tell both of my cards are paired and validated correctly. I am hoping someone else has had this problem and found a fix or what the next step i should take is. I am not thinking it is the cable card because it recieves the channels fine for a while before they go blank. This is my first step taken as the tivo support is closed tonight and hte second cable guy i had out didn't know what he was doing. Any help would be appreciated. Thanks.