I got a HD box from comcast today. I hooked it up to my TV using the HDMI cable. For some reason, the closed captioning is on and I cant turn it off. When I go through the menu, the closed captioning part is grayed out and I cannot click on it. When I click the caption button on the remote, it says Information not available. When I hook up the HD box using the RF cable instead, I can turn off the closed captioning. I tried both HDMI inputs and cannot turn off the closed captioning. I called Comcast and they say there is no on/off switch on their cable box. Am I doing something wrong?