Duplicate of Ticket #7442.

# diff -c mailbox.php.orig mailbox.php
*** mailbox.php.orig    2008-09-22 11:28:35.000000000 -0600
--- mailbox.php 2008-12-02 11:52:02.000000000 -0600
***************
*** 885,891 ****
   echo $mf_template->fetch(IMP_TEMPLATES . '/mailbox/message_footers.html');

   /* If there are 20 messages or less, don't show the actions/navbar again. */
! if ($pageOb->msgcount > 20) {
       $a_template->set('isbottom', true);
       echo $a_template->fetch(IMP_TEMPLATES . '/mailbox/actions.html');
       if ($n_template->get('use_folders')) {
--- 885,891 ----
   echo $mf_template->fetch(IMP_TEMPLATES . '/mailbox/message_footers.html');

   /* If there are 20 messages or less, don't show the actions/navbar again. */
!  if ($pageOb->end - $pageOb->begin > 20) {
       $a_template->set('isbottom', true);
       echo $a_template->fetch(IMP_TEMPLATES . '/mailbox/actions.html');
       if ($n_template->get('use_folders')) {

The navbar at the bottom of the mailbox listing is supposed to display 
if there are more than 20 messages on the page.  But the code tests 
the number of messages in the mailbox, not the number on the current 
page.