cell with defined content in a crosstab is empty

[philelmousse]

Hello,

I have a crosstab and one cell has defined content. I set the report's page properties with all item of my query. I also uncheck "section detail query" in crosstab properties.

My data item is a multiplication and when i run each element of that item i'm able to get the different values.

[philelmousse]

I can see the result when i have a data item like that in the singleton :

total([cost_monthly_actuals]within set [CATEGORY])

but when its something like that :

total([cost_monthly_actuals]within set [CATEGORY]) - total([cost_monthly_actuals]within set [CATEGORY],[SUB_CAT1])

its blank... I dont understand