Problem reconciling an account

I am reconciling my AMEX account and a beginning cleared balance keeps showing up. It's the same account I've been manually reconciling with paper bills for 15 years and a few months back I finally broke down and started downloading transactions. I have tried to un reconcile the previous months transactions and then the cleared balance starts with the month before that. Every prior month I un reconcile, the beginning balance goes to the prior month. I'm three months back and it keeps doing this. Any suggestions would be appreciated.