pagination incorrect when using groups with parents/children

If you view the members of a group where the group has children groups, the total count and page navigation is incorrect. two queries are generated with regard to this search – one which is simple, counts the records, and generates the page navigation, and a second which has the full set of records. the first is incomplete – it looks like it doesn't properly recurse to the children, thus rendering an incomplete count and incorrect pagination.

to reproduce on demo:
http://drupal.demo.civicrm.org/civicrm/group&reset=1
view contacts for "test parent" group
click "last" to go to the last page. note that the last contact begin with "r", but if I click "s" in the alpha navigation I can view additional contacts.