[Dovecot] PLAIN-MD5 passwords?

[Peter Clark]

    After I found out that {CRYPT} doesn't support passwords longer than 8 
characters, I decided to switch over to MD5 for user passwords in my LDAP 
database. However, while I have no problem with Postfix + SASL, Dovecot fails 
to authenticate.

Relevant bits from /etc/dovecot-ldap.conf:

user_attrs = mailAddress,,,,,
# The search string is identical to what's found in /etc/saslauthd.conf:
user_filter = (&(|(uid=%u)(mailAddress=%u))(status=active))
pass_attrs = mailAddress,userPassword
pass_filter = (&(|(uid=%u)(mailAddress=%u))(status=active))
default_pass_scheme = PLAIN-MD5

When I try to connect using either KMail or SquirrelMail (which worked just 
fine before I switched schemes), the following error appears 
in /var/log/syslog:
ldap(user at mydomain.tld): password mismatch

But when I try 'testsaslauthd -u user at mydomain.tld -p longpassword' it 
authenticates just fine.
    I have the line 'password-hash   {MD5}' in /etc/ldap/slapd.conf, and I 
used 'slappasswd -h {MD5}' to create the MD5 versions of the passwords. 
Dovecot is v. 0.99.11. If I can't figure out how to get it to work with MD5, 
I guess I'll have to go back to CRYPT, but it would be nice to have longer 
passwords...
    :Peter