Formula flip the sign between child and parent account member

Question

I have created two accounts as below which is parent to the child (670122) and child (670122.01) account and my account dimension looks as below
Account    PARENTH1     GROUP          ACCTYPE     RATETYPE
670122        670120         Profit & Loss            EXP           AVG
670122.01  670122         Profit & Loss            EXP          AVG     
PRETAX        INCOME         Profit & Loss            INC          AVG     
Now I have added the simple formula in the child account 670122.01 in the formulah1 column as [Account].[PRETAX] Which is Income account but when I retrieve the data  using EVDRE(), the Values are shown as below
670122.01     670122
3,398,006.86      (3,398,006.86)
Why do the parent and child has different sign when both accounts are same account type as Expense. Instead of formula if I put hardcoded value, then both parent and child accounts has the same value (not flipping the sign)

Answer 1

We are using BPC 5.0 and SQL Server 2005
The hierarchy is like this
670120 -> 670122 -> 670122.01
The dimension formula is in 670122.01 as like this ( [Account].[PRETAX]-[Account].[665000] ), 665000 is a expense account and pretax is income account
When I do the EVDRE on those above accounts
670120     670122     670122.01
(13,228,910.18)     (13,228,910.18)     13,228,910.18
When 670122.01 is rolled up to next immediate level, the value in 670122 has negative value. 670122 is rolled up to 670120, but they both have same value - Is this a known issue in the BPC 5.0?