I might suggest, if you're having trouble with the cable TV part only, contacting the cable company to see if they can do a hard-reset or a firmware update on your cable box. In most cases, this can be performed by them while you're on the phone.
If you'd rather not call, you can try to reset the cable box by unplugging the unit for a minute and then plugging it back in and powering it up.
I have a Samsung HT-C6600 Blu ray home theater system and the sound cuts out when watching cable TV. DVDs are fine. I replaced the cable box/hdmi cable, the blu ray player, the optical audio cable, even the new samsung TV and it still does it. Sound does not cut out if I listen to the TV speakers so it seems like the Blu ray player to me. I tried to update the SW but keep getting an error (tried 2 different usb drives and burned a dvd). I'm thinking this model has problems. Anyone else experienced this? Is there a fix?