Random loss of television signal

We are randomly losing the signal to both of our televisions. One is wired on Cat5 and the other one is wireless. We've had technicians here multiple times and basically everything has been replaced, the RG, the DVR, the WAP and the wireless receiver. We never lose telephone nor Internet. We have to reboot the set-top unit to clear the air in most cases. Some days it may happen 3 or 4 times other days it may be 10 or 12 times. We are on bonded pair with an NVG589. Error rate is practically nothing, -- Written using Dragon NaturallySpeaking