I closed on my house in July 2009. By October 2009, the mortgage had been sold to WF. I was told beforehand that this would happen, so it wasn't a concern. However, only two of the three bureaus lists the original loan as closed/zero balance. The third (I think it's transunion... I don't have the report in front of me) has it listed as if it were still active, owing the full amount I owed before it was sold, with no data had listed since my last payment. So for that bureau, my total debt is almost twice what it is for the other two.
The question is... if I ask to have it removed, will it increase or decrease my credit core? Any ideas?
Don't do that! You'll lose its contribution to your length of history, plus a healthy tradeline (credit account), assuming that it had no lates.
Find out for sure which CRA shows this. And you need to look at the full report directly from the bureau, not one from a monitoring service. You'll know it's a full report if it includes soft inquiries in the inquiry section. Third-party monitoring service reports are very prone to erroneous reporting, and it's possible that it's OK on the full report, which is the report that is used to calculate your FICO scores.