said by IllIlIlllIll 
:while i concur with your statement....
in the meantime, while the persons tv and computer begin the slow process of damage from a small amount of current passing through them, who is going to acknowledge and fix the hazardous problem in a timely manner ?
the cable company ?
the electric company ?
you know they will both blame each other for the problem and it will drag on until either of the persons devices are severly damaged as a result, and then the person will look to blame one company or the other.
i think the best sugggestion would be to give the cable company a call, since that is more than likely where the problem lies.
but be prepared for a fight with them acknowledging the issue and having it corrected in a timely manner.
in the meantime, i see no harm in using the device i suggested as a means to prevent further damage to the electronic equipment until the issue is resolved.
should his electronic equipment/computer get severely damaged as a result of not using the device, i wish the person lots of luck attempting to get compensated from either the electric company or cable company, as we all know, filing a claim with either company, the paperwork, estimates, time it takes to be compensated, and the irrelevant fighting between the two trying to blame each other and not acknowledging the issue exists, makes the idea of using the device i suggested alot easier - for the time being.
That's *assuming* that the problem lies with the cable company! Have we determined whether this is the problem? I'm doubting it since the OP hasn't mentioned any other problems with his home theatre. Unfortunately I have seen plenty of these problems caused by noisy laptop power supplies and poorly designed audio sections of laptops. I encounter it way too often, no cable feeds anywhere close to the systems in question. The safest and most effective way to eliminate this problem is through the use of an audio and/or video isolation transformer, or using better components that are not susceptible to such problems.
