The system is designed so that your period-end (month-end) statements show a beginning balance as of the previous billing date (typically a month ago) with details of each invoice since then also showing. This is done by using the Roll-Up All Invoices procedure.
If this is not what your statements show, one of two things could have happened:
1. Too much detail shows on the statement. This means that roll-up date is too far back. To fix it, use the Roll-Up All Invoices procedure using the previous months billing date.
2. Not enough detail shows on your statements. This means that the roll-up date is not back far enough. To fix it, use the Roll-Up All Invoices procedure using the date you want to show details back to (again, this should be previous months billing date).
In both cases, make sure that Rental Charges and Finance Charges are turned off so that they do not get charged again. Then re-run Prepare Statements, Print Statements, and Roll-up All Invoices.