Comment 18 for bug 155681

Same problem, after installing pyrex-mode, which installed python-mode and pymacs.
Purged the three and now I can use the emacs22 python mode.

 dpkg -l | awk '/emacs/{print $2,$3}'

now gives me

emacs 22.1-0ubuntu5.1
emacs-goodies-el 27.1-1
emacs22-bin-common 22.1-0ubuntu5.1
emacs22-common 22.1-0ubuntu5.1
emacs22-gtk 22.1-0ubuntu5.1
emacsen-common 1.4.17

It's a real pity though, I will have to switch to emacs-snapshot to use pyrex-mode and the original python-mode