[Admin]

In member.php, replace this:

  if ($userinfo[posts]!=0 and $userinfo[lastpost]!=0) {

with this:

  if ($userinfo['usergroupid']==5 or $userinfo['usergroupid']==7 or $userinfo['usergroupid']==6) {
    $lastpostdate="Can't see this info";
  } elseif ($userinfo[posts]!=0 and $userinfo[lastpost]!=0) {

and change the red part.