I think checking up in the past for me was a way to not look at what I had to look at in myself. My most recent ex and I broke up last Thanksgiving, but had contact for months after. He is a musician, so he has a website, a myspace, and plays at a famous club here in the city and is splashed all over that. Since the day we broke up and I decided to get serious about my recovery, I have not once looked at any of those websites. It would only hurt me to see things about him considering at one point I was such a big part of his life.
When you are really ready to focus on yourself, it won't be so hard to ignore him and check up on him.