Accounts Payable Trial Balance report result doesnot match with the calculate balance owed result

 first issue: problem in Accounts Payable Trial Balance report

when i "calculate balance owed" for a specified supplier through the invoice form

  and run the Accounts Payable Trial Balance report for the same supplier

the 2 results do not match with each other 

there are .02 cents difference between them

as shown in attached screen shots (form,report)

second issue: APTBRPT Java concurrent program

when i checked the report Accounts Payable Trial Balance in system administrator responsibility

I found that it's type is Java concurrent program (APTBRPT), how can i open this to see the SQL query inside or how can i customize it