Copy forecast to ledger in AX R2 CU6

Hi All,
I have the following issue: firstly when we add the expenses to the project budgeting in the Project Management Module, and press (Copy forecast to ledger), then the expenses amounts will be transferred to (All budget register entries) form,

After that, if I do a revision ( - or + ) on expenses in the previous project budgeting form in the Project Management Module , and press once again (Copy forecast to ledger), then i’ve got a wrong amounts in the transferred data in (All budget register entries) form,

My question is this a bug in Dynamics AX and need a special hot fix (Noting that i used MS dynamics AX R2 CU 6), or is there any missing step or setup i have to do to get right revision values??
Your response will be highly appreciated
Best regards,