If the customer has finalised transactions on the statement date, then these will be included in the printed statement but will not be included on the screen (and print) output.
This behaviour matches the CSH text but is confusing to the user.
For more background see http://www.openvpms.org/forum/reportingdebtors-screenstatement-mismatch
Suggested fix: include finalised transactions on the statement date in the screen (and print) output so it matches the statement. (And adjust the CSH text).
Also - if possible include the statement date in the special archetype CUSTOMER_BALANCE so that the output from the Print button can include this on the printout.