Collective Bill Print - Issue - Billing Multiple Period in Same Collective

Hi All

I am facing issue while printing Collective Bill created for multiple billing period. For example

Child Bill - Month 01 - 200 $

Child Bll  - Month 02 - 300 $

Child Bill - Month 03 - 400 $

All the child bills are created on the same day.

Now one collective bill in created for three billing period ( 01 , 02 ,03) . When I check the the T_DOC_HEADER internal table in collective bill form in debug mode  I see all three child invoice which adds up to 900 $. Ideally only one child invoice ( Month 03) should have been picked by the standard logic . Has any one faced this issue earlier.

Thanks in advance.

Regards

Neetesh