[Dovecot] userdb prefetch not working for passdb sql

[dovecot-ri]

Hi all,

I'm using 1.0.beta3 and having problems using userdb prefetch in conjuction with passdb sql.  Here are my mail logs when I log to virtual account "testuser at mydomain.com" by doing "telnet localhost 143":

Mar 26 15:15:47 imapserver dovecot: Dovecot v1.0.beta3 starting up
Mar 26 15:15:49 imapserver dovecot: auth-worker(default): mysql: Connected to (null) (mail)
Mar 26 15:16:03 imapserver dovecot: auth(default): client in: AUTH      1       PLAIN   service=IMAP    secured lip=127.0.0.1   rip=127.0.0.1   resp=<hidden>
Mar 26 15:16:03 imapserver dovecot: auth-worker(default): sql(testuser at mydomain.com,127.0.0.1): query: ***snipped, very long***
Mar 26 15:16:03 imapserver dovecot: auth(default): client out: OK       1       user=testuser at mydomain.com    
Mar 26 15:16:03 imapserver dovecot: auth(default): master in: REQUEST   1       16001   1
Mar 26 15:16:03 imapserver dovecot: auth(default): passwd(testuser at mydomain.com,127.0.0.1): unknown user
Mar 26 15:16:03 imapserver dovecot: auth(default): prefetch(testuser at mydomain.com,127.0.0.1): userdb_uid not returned
Mar 26 15:16:03 imapserver dovecot: auth(default): prefetch(testuser at mydomain.com,127.0.0.1): userdb_gid not returned
Mar 26 15:16:03 imapserver dovecot: auth(default): userdb(testuser at mydomain.com,127.0.0.1): user not found from userdb
Mar 26 15:16:03 imapserver dovecot: auth(default): master out: NOTFOUND 1
Mar 26 15:16:03 imapserver dovecot: imap-login: Internal login failure: user=<testuser at mydomain.com>, method=PLAIN, rip=127.0.0.1, lip=127.0.0.1, secured

The MySQL query is long and complicated, but here's what it returned when I copied and pasted it into mysql:

user         testuser at mydomain.com
password     {SSHA}BRuPgonpb8Zd+0NaFH2G6dT47m3mT43w
userdb_home  /var/mail/mydomain.com/testuser
userdb_uid   vmail
userdb_gid   vmail

All of these values are correct.  It seems to be ignoring the userdb_* fields.  It works when I don't use prefetch, and it also works when I do use prefetch but change the SQL query to return "testuser" instead of "testuser at mydomain.com" in the user field.  Anyone know why?

Here's my dovecot.conf in case it proves useful:

first_valid_uid = 900
mail_debug = yes
default_mail_env = maildir:%h/.maildir 
maildir_copy_with_hardlinks = yes
protocol imap {
  login_greeting_capability = yes
}
protocol pop3 {
}
auth_verbose = yes
auth_debug = yes
auth default {
  mechanisms = plain
  passdb sql {
    args = /etc/dovecot/dovecot-sql.conf
  }
  passdb pam {
    args = "*"
  }
  userdb passwd {
  }
  userdb prefetch {
  }
  user = root
}
plugin {
}

Thanks!