Intermittent recording problem on certain Prime Time Programs.. Instead of recording full hour of a program I am interested in, say from 9 pm - 10 pm, it will start recording around one hour later. When you go to watch you get the last 2-3 minutes of the program you want to see and the start of the next Prime Time program. This started around a month ago and it seems to only effect Prime Time Channels. Any advice as to the cause???