[Mediawiki-l] "sessionfailure" message when delete/update files

[Michael Lee]

I configured Mediawiki 1.5.7 to use the REMOTE USER authentication
method described here:

http://meta.wikimedia.org/wiki/Auto_Login_via_REMOTE_USER

If a user logs on under Windows with Internet Explorer and attempts to
delete or update a file, it works without problems.  This Windows/IE
user is logged onto the corporate domain controller, so he is not
prompted for username/password upon entering the Wikimedia site.

However, if a user logs on using Mozilla Firefox, the same action
reports the following error message:

"Internal error
There seems to be a problem with your login session; this action has
been canceled as a precaution against session hijacking.  Please hit
"back" and reload the page you came from, then try again."

Going back and refreshing still has the same problem.  I've also noticed
that IE users who did not initially log on to the Windows domain (so
they're prompted for username/password upon entering the Wikimedia site)
experience the same problem.

I enabled debug logging, and this is what it reports after pressing
"Confirm" to deletion:

Start request
POST /mediawiki/index.php?
title=Image:blah.gif&action=delete
Host: blah-machine
User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.7.12)
Gecko/20060130 Red Hat/1.0.7-1.4.3 Firefox/1.0.7
Accept: text/xml,application/xml,application/xhtml
+xml,text/html;q=0.9,text/plain;q=0.8,image/png,*/*;q=0.5
Accept-Language: en-us,en;q=0.5
Accept-Encoding: gzip,deflate
Accept-Charset: ISO-8859-1,utf-8;q=0.7,*;q=0.7
Keep-Alive: 300
Connection: keep-alive
Referer: https://blah-machine/mediawiki/index.php?
title=Image:Snl_tbird_logo_trans.gif&action=delete
Cookie: tz_offset=-28800; mediawiki_dbUserName=BlahUser
Authorization: Basic
Content-Type: application/x-www-form-urlencoded
Content-Length: 73

Main cache: fakememcachedclient
Message cache: mediawikibagostuff
Parser cache: mediawikibagostuff
Using reader #0: localhost...

Block::load: '192.168.3.2', '34', 1
** no caching **
WARNING: Abrupt exit
in /data/www/html/mediawiki-1.5.7/includes/GlobalFunctions.php at line
437
WARNING: Abrupt exit
in /data/www/html/mediawiki-1.5.7/includes/OutputPage.php at line 726
WARNING: Abrupt exit
in /data/www/html/mediawiki-1.5.7/includes/ImagePage.php at line 402
WARNING: Abrupt exit in /data/www/html/mediawiki-1.5.7/index.php at line
179

Does anyone have any suggestions?  Thanks.