In the FICO reports, there's a box that says "worst delinquency". That box likely did say something like "none reported" prior to the score change. Unfortunately, it may have been changed to "60 days past due". That comment box does have a huge impact on your scores. I too have First Premier and they are just past the 7 yr mark. I had a CO with them in 2000. Monthly, they change it from "paid collection" to "120+ days past due". Because of that, the score yo-yos back and forth by about 30 points, if I recall correctly.
I don't know why that happens. In my case, FP is set to be removed in June and have no plans to fight it. However, it just doesn't seem right. And I could be wrong on the cause, but I'm feeling good with this and that is my final answer.