Can't list all Project Areas in BIRT report

Hi,

I am using COMMON_SNAPSHOT, and LIVE_CONTRIBUTOR table. When I put some contributor name as parameter in CONTRIBUTOR_NAME, I should get all Project Areas where that contributor is formal member.
So, I succeeded to build that report, but some Project Areas are not shown.
I should understand this situation if I am using WORKITEM_SNAPSHOT, because you can't get project areas in list where you have not some work items created.

Any idea about this?

Regards,