How do I Unreconciled External Transactions the system advised that are accounted for?

Our customer automatically reconciled a bank statement. There were some transactions that have no 'pending items' and the system created external transactions. Later on, doing further searching, the user found the pending items on a different date range. Now, we have these external transactions that we need to 'unreconcile'.

• When we try Banking, Reconcile Statements, Semi-Manual Reconciliation, we search for a date range, the system displays the Bank Transaction to the left of the screen and the System Transactions on the right hand side of the screen with the 'Select ' button grayed out.
• When we select the Bank Transaction and click "Select Matches" the system displays this Message: