Exim 4.1 says PAM module not found

[Hanasaki JiJi <hanasaki@hanaden.com>]

I am running exim built under Debian Woody.

Where can I find the docs to configure pam.d/exim to authenticate for
exim?  the log says "cant find moudle"

Any input on how to config PAM so exim can find it?  exim 3.x did PAM 
fine.  The same entries are still in /etc/pam.d/...

Exim 4.x was built with PAM support

Thanks