I've had the same problem in the last few months. I've been able to cope with it, but in the last few weeks its gotten worse. The remote just stops working, but then the cable box just starts to change channel then the volume starts going crazy. Now with people stating low batteries or even energy bulbs, I've got brand new batteries in and normal bulbs. The TV is a normal (old) tv lol, so I cant understand what the problem is except for the samsung 2100 box. If the remote isn't working when I want to change the channel I hold down the TV button and thats when it all goes crazy.
I just feel like the remote has lost contact with the cable box and the Tv button gets the connection back and catches up with the commands that you've been trying to press.
I've even looked at the box maybe even overheating so I've moved it twice and it still does it, so the only conclusion I can come up with is the box must have a fault somewhere.
Now if someone could give me a pointer to try and fix this and prove its not a faulty box I'd be very grateful. As I don't really wan to phone up VM CS as I always seem to get through to India