Hello,
About the sign logic, please refer to SAP note 33178
The following applies to direct postings from FI to profitabilit
segments:
- Debit postings of costs and credit postings of revenues ar
transferred with a 
sign. The corresponding offsetting
entries are transferred with a 
sign.
For example: One G/L is a sales deductions account. Since sales
deductions are handled like costs. If you debit sales deductions, it
will be transfered as positive value in COPA, and if you credit sales
deductions, it will be transfered as negative value.
If you want to get a different result in the report output you need to
adjust your customizing of teh key figure scheme.
Regards,
Ronghua Fan