A revelation, sort of.....
I've been experience the same problems with my MCE 2005 box that others are reporting. I live in Canada and I use Shaw digital box for my signal. Everything was working great for two years with only minor issues until just before Christmas. I noticed the error msg for everything that I was trying to record. After a few weeks, I give up and unhooked my MCE 2005 box as we had watched all the recorded shows. I had almost given up on the everything and was going to purchase a PVR from Bell ExpressVu and leave Shaw because they where preventing me from recording anything. After some playing around with my MCE 2005 unit, I notice the digital box was on channel 313, which happens to be a ppv channel for Shaw. I did some testing, I would set up to record a show and leave the channel on 313, I would get the error msg, saying copyright restrictions prevent recording..... I would try and record the same show the next day only change the channel to a non ppv channel, a channel that I was able to get a feed from using LiveTV. I found that I was able to record without issue. I tried again and again, and what I found is that MCE 2005, at least the way mine is configured starts to record before it changes the channel, which in my case gives me the error msg. As for why I was on that channel or a channel that I don't subscribe to.....all I can say is too many remotes and kids that think they can change channels.
My problem seems to be solved