We've noticed this here and there on various channels over the past several months. We had a freeze or lock up happen this afternoon on channel 626 and VOD my wife reported. I contacted our local office and they're sending a truck by tomorrow to check our signal strength.
Hope they get that fixed for you. The problem on 660 has gone away. I've only ever noticed it regularly on 6 SD - never 6HD and only during storms. The problem with 660 was probably something at the headend which has been either taken care of or is intermittent which is a bit more difficult to track down, making the tech's job difficult. If it happens again, I'll repost.
We had our service call today. The tech said they sent out a new signal a few weeks ago but some Moto boxes like our DCH3200 did not get it. He replaced the box with a new one and signal strength seems better. He also said that RCN employees are using the Tivo boxes in our area. Just the enhancements in the box for TV viewing aside from the DVR make it sound worth getting when it rolls out for testers in Philly. His favorite feature was the ability to rent old movies from Netflix.