Hi, guys. I'm new to the forum. Wondering if anyone could shed some light on this problem. I have a the Scientific Atlantic 4200HD with Firewire from Cablevision. I also have the JVC HM-DH40000 D-VHS deck. Everything works. Except when I turn on the VCR to I-1 for Hi-Def thru the firewire, I get no picture or sound. I thought it was the cable box so I exchanged it for another one. Same problem. What I see on the I-1 is the VCR recognizing the cable box 4200HD, picture becomes letter-boxed for HD, but then it goes blank. No picture. To me it says that the JVC 40000 is working because it recognizes the cable box. Called Cablevision, they said it might be that certain 4200HD cable boxes does not have the 1394 ports actived from the factory. That only an experience Cablevision Tech will be able to determine this with testing equipment. (EVEN EXCHANGED THE FIREWIRE FOR A NEW ONE, SAME PROBLEM). If anyone has any ideas or suggestions that could solve this problem, I would really appreciate it. If not I would have to wait for Cablevision to come in on Monday. Thanks.