I can honestly say that I have never had a problem with a patch or new pack but that could be because I don't use mods. I have occasionally dabbled in a bit of cc but I never keep it my game for more than a few days because it scares me!! XD I decided to back up my saves this time just because of what other people were saying really and I am VERY glad I did. I was having this problem pre-patch so I am completely sure it was nothing to do with it but the threat of problems with the patch has probably saved me a lot of heartache!