|How are you watching them? what program? have you tried burning to dvd and playing on your home dvd player.|
I recall having this problem once, but I can't remember what I was doing at the time, but I do remember the recording was fine after I converted it to dvd.
It could have been in XP or Vista, I have been using Windows 7 since the Beta release and now the RC, I havn't had a repeat of the problem.