Calculated Measure error

Hi.
I am working on a cube for schools, precisely analysing student absences.

I have two measures belonging to two measure groups where each measure group is linked to all the dimensions. These measure are : count of absences ,number of periods.

The calculated measure i'm trying to do is : (count of absences /number of periods )where number of periods != 0.

case

when [measures].[number of periods]= 0

then 0

else ([measures].[count of absences]/[measures].[number of periods])

end

in the browser with school,class,student dimensions as rows and both [absence count] and [number of periods] as measures, the data is displayed correctly.

however when i drag the calculated measure into the cube browser i get dummy data where the joins between students/classes/schools are lost...as if the 3 dimensions are cross joined...so i get all the students of the dimension student belonging to each class .

i don't know why this is happening: each measure alone is working but when i combine them both into one measure the data is mixed up.

What could be the problem?

thanks for your help

Christina

it worked..!!!

i put the [number of periods] in the non-empty behaviour field...

i didn't know that it was that important....

thanks anyway

Christina