Emacs 24 (from https://launchpad.net/~cassou/+archive/emacs) on Ubuntu 
11.10 with auto-complete package http://cx4a.org/software/auto-complete/ 
installed from git https://github.com/m2ym/auto-complete

Crashes seemingly randomly when displaying the auto-complete pop-up 
window but always at the same location - see attached gdb bt full backtrace.

I am not able to reliably reproduce this (as I said above it seems 
random), but it seems to happen a few times every day and always when 
showing the pop-up window.

The following is my auto-complete config

;; auto-complete mode
(add-to-list 'load-path (expand-file-name 
"~/.emacs.d/vendor/auto-complete"))
(require 'auto-complete-config)
(add-to-list 'ac-dictionary-directories 
"~/.emacs.d/vendor/auto-complete/dict")
(ac-config-default)
(setq ac-auto-start 1) ; make autostart after entering a single character
(setq ac-auto-show-menu (+ ac-delay 0.1)) ; show menu after 100ms
;; quick help has to be after menu so again set to 100ms more
(setq ac-quick-help-delay (+ ac-auto-show-menu 0.1))


In GNU Emacs 24.0.91.1 (x86_64-pc-linux-gnu, GTK+ Version 3.2.0)
  of 2011-11-29 on osmium, modified by Debian
  (emacs-snapshot package, version 1:20111128-1~ppa1~oneiric1)
Windowing system distributor `The X.Org Foundation', version 11.0.11004000
configured using `configure  '--build' 'x86_64-linux-gnu' '--host' 
'x86_64-linux-gnu' '--prefix=/usr' '--sharedstatedir=/var/lib' 
'--libexecdir=/usr/lib' '--localstatedir=/var' 
'--infodir=/usr/share/info' '--mandir=/usr/share/man' '--with-pop=yes' 
'--enable-locallisppath=/etc/emacs-snapshot:/etc/emacs:/usr/local/share/emacs/24.0.91/site-lisp:/usr/local/share/emacs/site-lisp:/usr/share/emacs/24.0.91/site-lisp:/usr/share/emacs/site-lisp' 
'--without-compress-info' '--with-crt-dir=/usr/lib/x86_64-linux-gnu/' 
'--with-x=yes' '--with-x-toolkit=gtk3' '--with-imagemagick=yes' 
'build_alias=x86_64-linux-gnu' 'host_alias=x86_64-linux-gnu' 
'CFLAGS=-DDEBIAN -DSITELOAD_PURESIZE_EXTRA=5000 -g -O2' 'LDFLAGS=-g 
-Wl,--as-needed' 'CPPFLAGS=''

Important settings:
   value of $LC_ALL: nil
   value of $LC_COLLATE: nil
   value of $LC_CTYPE: nil
   value of $LC_MESSAGES: nil
   value of $LC_MONETARY: nil
   value of $LC_NUMERIC: nil
   value of $LC_TIME: nil
   value of $LANG: en_AU.UTF-8
   value of $XMODIFIERS: nil
   locale-coding-system: utf-8-unix
   default enable-multibyte-characters: t

Major mode: Lisp Interaction

Minor modes in effect:
   paredit-mode: t
   eldoc-mode: t
   diff-auto-refine-mode: t
   nxhtml-menu-mode: t
   nxhtml-tag-do-also: t
   popcmp-group-alternatives: t
   popcmp-short-help-beside-alts: t
   mlinks-active-links: t
   rngalt-minimal-validation-header: t
   rngalt-display-validation-header: t
   flyspell-mode: t
   yas/global-mode: t
   yas/minor-mode: t
   global-auto-complete-mode: t
   auto-complete-mode: t
   ido-ubiquitous-mode: t
   autopair-global-mode: t
   global-undo-tree-mode: t
   undo-tree-mode: t
   which-function-mode: t
   global-semanticdb-minor-mode: t
   global-semantic-idle-scheduler-mode: t
   semantic-mode: t
   electric-layout-mode: t
   electric-indent-mode: t
   delete-selection-mode: t
   cua-mode: t
   global-auto-revert-mode: t
   display-time-mode: t
   show-paren-mode: t
   mouse-wheel-mode: t
   file-name-shadow-mode: t
   global-font-lock-mode: t
   font-lock-mode: t
   auto-composition-mode: t
   auto-encryption-mode: t
   auto-compression-mode: t
   column-number-mode: t
   line-number-mode: t
   transient-mark-mode: t

Recent input:
M-x r e p o r t <return>

Recent messages:
xhtml-loader.rnc was ok
(No changes need to be saved)
Loading /home/apm/.emacs.d/vendor/nxhtml/nxhtml/nxhtml-autoload.el 
(source)...
majmodpri-apply-priorities running ... (done)
Loading /home/apm/.emacs.d/vendor/nxhtml/nxhtml/nxhtml-autoload.el 
(source)...done
Nxml/Nxhtml Autostart.el loaded in 0.9 seconds
Loading /home/apm/.emacs.d/vendor/nxhtml/autostart.el (source)...done
Pymacs loading ropemacs...done
Starting new Ispell process [british] ...
For information about GNU Emacs and the GNU system, type C-c C-h C-a.

Load-path shadows:

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