from our pam maintainer:
23:33 < vorlon> jcristau: meh, I'm currently working on redoing how
/etc/pam.d/common-* are managed, after which that won't matter,
so I think you can sit on the bug for now
So /etc/pam.d/xdm will stay as-is for now, and this bug will hopefully
be fixed by the pam package in the lenny+1 timeframe.
Cheers,
Julien