it should work, it looks like maybe the setting didn't work for you.
Did you add
enable_processing_unique_visitors_range = 1
below [General] section ?
to make sure they are re-processed, delete the piwik_archive_ tables and try again ?
Did you add
enable_processing_unique_visitors_range = 1
below [General] section ?
to make sure they are re-processed, delete the piwik_archive_ tables and try again ?