I'm unable to reconcile a bank statement!

I've been a Reckon/Quicken member for aeons and have not had this problem ever before. I have entered all the transactions correctly (6 attempts prove it), I've even reconciled the account using the old fashioned calculator. It all works. But it won't reconcile in the software. I am -$9.99 out. There is a transaction for that amount which I have removed from the ledger and from the Scheduled Task, but that only leaves me with the account being out by -$19.98! I have removed the $9.99 transaction and even shut down the computer. As a last resort I printed the register and all the entries are correct. I'm at my wits end. At the same time as attempting to reconcile the problem account I successfully reconciled three other accounts. I can only assume I have a gremlin in the works. HELP ... PLEASE!