I don't know why your credit rating is how it is (or even what it is obviously lol) but when my mom and Yo were buying the house in California they both needed to improve their ratings. One of the things the guy helping suggested was that for any companies that showed you'd been delinquent they write them a letter explaining what had happened and ask they remove that from their rating. It didn't work with every company but enough did it to improve their ratings.