Problems with your line!
It sounds like there is problems with your cable line. Its usually a tel tel sign when you "get digital brake up" that something is going on with the cable line. Make sure that you are not using the cheap cable splitters and make sure that the all connections with in your house are connected tight, especially the split connections.
If you experience the same problem, call up technical support and have a technician come out. Explain to them the problem and ask them if to check the outside wiring. If you are not happy with your hardware, you could always go to the Optimum store and ask them for a newer model box. You problem will not be solved unless you make them aware of it, been persistent always helps!!