RNG200 DVR Problems

Comcast delivered a Cisco RNG200 DVR this week. Since it's been hooked up we've had repeated picture/sound)interruption--"freezes" and stalls of about 20 seconds, then picture distortion of a few seconds, and then a gradual return to normal picture and sound. This sequence only happens on higher-number channels, which may mean something. Comcast claims they are not having problems with their digital signal, although we are in the Houston area in the wake of Hurricane Ike and Comcast has certainly had ongoing various problems. Even so, nothing like this was happening before the RNG200 hook-up. Also, and of much greater concern--is that the RNG200 box, which is silver-toned metal heats up to an alarming temperature! It remains hot to the touch even when turned OFF. We have unplugged it every night out of concern. Comcast is scheduled to come and bring a replacement box and we are very curious as to whether it will also be an RNG200 and if so how will it perform? Maybe we just got a lemon. Has anyone else experienced good or bad performance from an RNG200?