Comcast XFINITY TV → CBS/DVR/On Demand..Coincidence?

I swear, every week it is another problem with my DVR.

This week, when I record a show off of CBS, it never records the full show. For example, I recorded the new Amazing Race and it only recorded 1:40 instead of the 2:00 it was supposed to.

Tonight, I recorded Survivor, and it only recorded the first 10 minutes.

On other networks, I'm not having a problem. I really wonder if it is a Comcast Conspiracy so that you have to watch it OnDemand the next day and pay the $.99

Last month it was getting billed for Cinderella Story, and some other movie that I've never watched. The month before it was not really working at all. I think in the last 6 months I've been through 5 DVR's and it's just nuts. If we had to call the gas company or electric company this often, all hell would break loose. But since it is the monopoly known as Comcast we have no choice but accept it or go to dish. I really wish my town would allow other cable providers as this is just getting crazy.