timsieved[]: badlogin: ...[] PLAIN no mechanism

[Adam Williams]

We've had a perfectly functional Cyrus IMAPd/SIEVE server for quite some
time now.

In order to fix some bugs and get direct LDAP authentication I upgraded
from our old SASL 2.1.5 to the latest, and reconfigured saslauthd to use
LDAP instead of PAM (this involved chaning only
/etc/sysconfig/saslauthd) and restarting saslauthd.  Didn't touch
/etc/imapd.conf, etc...

I tested IMAP authentication and it worked (and was much faster and
saslauthd threads had a smaller memory footprint).

But now smartsieve (a web SIEVE script tool) can't login to timsieved,
it gets something like -

Jul 29 14:45:40 sardine timsieved[19545]: Couldn't find mech PLAIN 
Jul 29 14:45:40 sardine timsieved[19545]: badlogin:
kohocton[192.168.1.5] PLAIN no mechanism available

But logins to imapd work fine -

(14:47:39) whitemice: Jul 29 14:22:16 sardine imapd[18805]: login:
kohocton[192.168.1.5] jtimmer plaintext+TLS 
Jul 29 14:22:25 sardine imapd[18805]: login: kohocton[192.168.1.5]
jtimmer plaintext+TLS

How is timsieved authentication different than imapd authentication? 
Confused.

Our /etc/imapd.conf file -
configdirectory: /var/lib/imap
partition-default: /var/spool/imap
admins: cyrus
timeout: 120
allowanonymouslogin: no
sieveuserhomedir: no
sievedir: /var/lib/imap/sieve
sieve_maxscriptsize: 64
sendmail: /usr/sbin/sendmail
hashimapspool: true
sasl_pwcheck_method: saslauthd
sasl_mech_list: PLAIN
postuser: shared
altnamespace: yes
tls_cert_file: /usr/share/ssl/certs/cyrus-imapd.pem
tls_key_file: /usr/share/ssl/certs/cyrus-imapd.pem