Updated 6Nov2015 to correct the fact that customers with old credit balances were being displayed when 'Show Credit Balances' was false.
Updated 4Nov2015 with R05 version which is significantly faster that the original.
This report provides an accurate debtors position at any date. To do this it examines when invoices were paid. This takes a lot of work and the report takes some time. If you want the current debtors position you should use the Debtors Report - Current - it is far faster.
The parameter selection screen is: