Fixed by:

http://lists.horde.org/archives/cvs/Week-of-Mon-20070402/066575.html

Just as an update to this we've removed the "Empty Trash Folder" 
action in /horde/imp/templates/mailbox/actions.inc.  Just can't risk 
nuking peoples' inboxes.  I'm wondering why it was put there in the 
first place considering there already is an empty trash button AND 
since the trash folder is the only one that has the secondary option 
for deleting.  Doesn't make sense.  I've commented out the following 
lines:



<!--

<?php if ($trashMbox): ?>

    <?php echo Horde::widget(Util::addParameter($mailbox_url, 
'actionID', 'empty_mailbox'), _("Empty Trash folder"), 'widget', '', 
"return confirm('" . addslashes(_("Are you sure you wish to empty this 
folder?")) . "');", _("Empty Trash folder")); ?>

<?php endif; ?>

-->



Personally I see no reason to uncomment that even if it gets fixed... 
but I don't like making too many local mods to the code so if the 
issue can be tracked down and fixed I'd consider putting it back in.

We've been having cases where users go into their trash folders and 
instead of clicking on "Empty Trash" they click on "Empty Trash 
Folder".  In certain cases (which I haven't been able to reproduce) 
Imp will delete the user's INBOX, leaving the trash folder intact.



I have not been able to reproduce this error, nor has there been a 
flood of complaints from users about it... but we HAVE had to restore 
5 inboxes from backups in the last week for this exact problem so 
there's definitely something wrong.



The ONLY thing that I can think of that might be related is when you 
look at the URLS you see the following:

(note that we've called the trash folder "WebTrash" to differentiate 
it from other imap trash folders)



https://webmail.ualberta.ca/mailbox.php?mailbox=WebTrash&actionID=empty_mailbox  (this is the empty trash button 
URL)



https://webmail.ualberta.ca/mailbox.php?actionID=empty_mailbox  (this 
is the "empty trash folder" link URL)



So since that link doesn't appear in any other folder you'd think they 
should be identical.



I'd recommend removing the "empty trash folder" link entirely.