linux4me2 on "Aggregating Usermeta From Blogs To Custom Table"

I don't know if this could be causing a problem or not, but you do have extra parentheses in some of your varable statements:
$kw_fname = (get_user_meta($current_site_admin, 'first_name', true));
should really be:
$kw_fname = get_user_meta($current_site_admin, 'first_name', true);
For form's sake, you could change that easily and see what happens.