Comment 16 for bug 673350

FWIW I have just encountered this bug on multiple Ubuntu systems here, a mix of 10.*, 11.*, and 12.04
All these systems run stock LaTeX and Emacs from the default repos. I have repaired the damage manually with the following steps using Synaptic (NOT the new Software Centre, which hides too much from view):

0. Back up your site-lisp and .emacs files somewhere safe
1. Remove completely ALL emacs* and related *.el packages
2. Exit Synaptic and run it again (otherwise it gets the dependencies wrong)
3. Install emacs23 and whatever other packages you removed in [1] including ispell
4. It will fail to complete because the soft-links in emacs23/site-lisp don't have any files at the end of them in emacs/site-lisp
5. In emacs/site-lisp/dictionaries-common, grab copies of debian-ispell.el, flyspell.el, and ispell.el from somewhere else (I used http://stuff.mit.edu/afs/athena/system/amd64_deb50/os-ubuntu-10.04/usr/athena/share/emacs/site-lisp/dictionaries-common but YMMV)
6. cd .. and repeat for debian-startup.el
7. Install something harmless like css-mode.el in order to trigger apt into trying to configure emacs23, and monitor the console carefully to see what directories it fails to stat
8. In my case, because I have a very full installation of TeX, I had to re-install latex-cjk-common, thailatex, and latex-cjk-thai for some obscure reason: your system will almost certainly be different, and you may have to re-install a different set of packages.
9. When it has finished rebuilding the ls-R databases it doesn't say so, so you need to close the window.
10. Copy back any personal .el files and/or your .emacs file from backup if they were removed.

This got my system back and working; I believe from other reports that it is the absence of the three ispell files that causes the configuration to fall over; quite why debian-startup.el was missing is not clear.