Analytical Reports created is showing unexpected result during excecution

I have created an OTBI Analytical Report with say, columns 'A' and 'B'. I need to update the column 'B' to 'C' making it dependent on 'A'. The logic to be executed is as follows:

C --> case when A=0 then 0 else B end.

I have 2 rows in this Report where this logic should work. Columns A and B are individually giving expected outputs. But when the mentioned condition is applied, the else case is not working properly. There is a reduction in the B value. I executed the report with small change in the logic as follows:

C --> case when A=1 then 0 else B end. also,