When running the Aged Debt report it is possible to filter by Controller, if an account does not have a controller or a different one to what is defined the transaction will not appear.
The Controller is set against the customer account:
From the Toolbar select Sales Ledger.
Followed by Customers.
Click the Customer tab.
Followed by the Main Sub tab.
RMB in the bottom half of the screen Modify Record.
Controller is the field.
Click Apply to save any changes.