Comment 7 for bug 134308

I ran into this too, and removing python-mode solved the problem.

Looking at the python-mode package's install scripts, it doesn't byte-compile the elisp for Emacs 22 (the fix doko is referring to).

However, the /etc/emacs/site-start.d/50python-mode.el file still gets processed by emacs22 and appears to shadow the builtin python-mode.

There seem to be two solutions here:
 1. make 50python-mode.el check the Emacs version
 2. install 50python-mode.el into a version dependent startup directory.