said by SpHeRe31459:
Yep put it on a UPS, lots of people do it for that very reason.
And sadly newer boxes do not change how fast the guide reloads, because it's not a function of the box per-say, the limiting factor is how Comcast sends the guide data over the cable network. It's sent in trickles over the out-of-band (OOB) stream which is a tiny little piece of bandwidth. It's a very "legacy" and lowest common denominator way to do the guide data, for old SD boxes that cannot do any other way.
The limiting factor is Moto and Comcast being too cheap to put a small flash chip in the boxes to cache the guide data. Or just use a small bit of the HD space fer cryin' out loud.
The answer is always a UPS, this will also help you avoid incomplete recordings due to power glitches.