It may be an IR interference where either the cable box or TV emits a signal that the other device's remote is not working properly with. Some users have tried to put tape (or tape a small piece of paper) over the cable box's IR sensor with mixed results, but I'm not aware of the television emitting an IR signal that should be over-riding the cable remote.
If this continues, you might try a different cable box. If that doesn't work, then you can request a service for your television.
I think my "search fu" is weak. Been diligently Googling different combinations but can't seem to find a solution... thought I'd ask here.
Samsung LN55B650 T1FXZA (Firmware: 2009/09/07_001012), purchased Feb '10
Comcast DCX3400 Motorola DVR Set-Top Box
(Got an Xbox and a DVD player but I think the top two are the ones who hate each other.)
When the TV's been off for a while and it gets turned back on, there's a good 3-4 minute delay where you can't control the volume (with either remote). During this 3-4 minute Bermuda Triangle period: With the Samsung remote, you can't even access the sources or the menu. With the Comcast remote, you can only access the menu (the channel toggle doesn't work either). After some research, it seems that others have had the same problem albeit with different models and cable boxes.
Any and all advice and/or hints are greatly appreciated...
P.S. I tried calling Samsung support but she told me to take the batteries out of the remote. Then told me to call back if I was still having the problem. *sigh*
(Help! it's driving me batty.)