[Dovecot] PAM authentication problem: MD5 vs crypt

[bhayden at umn.edu]

Here's a strange one. I have Dovecot set up on Solaris 9. The auth portion 
of the config is straight out of the box. Using PAM. We have most users in 
a dbm file which is just a series of key/value pairs: key is a username, 
and value is a string equivalent to a shadow entry. nsswitch.conf entry: 
passwd files dbm.

For historical reasons, some users have a classic 13-character Unix crypt 
password hash, while others have a 34-character MD5 hash. Here's the 
situation:

User location         pw Hash           Auth succeeds/fails
----------------------------------------------  
files                       crypt                 succeeds
dbm                       crypt                 succeeds
files                       MD5                  succeeds
dbm                       MD5                  FAILS


After two days of research, trussing, and etc, I am stumped. Does anyone 
have a thought?

-Brian