[Dovecot] Hang on login since 1.2.4

[Tom Sommer]

I upgraded a number of servers to Dovecot 1.2.4, and now suddenly I get
a lot of customers saying it takes a long time for them to log in.

I enabled all debug and see the following:

Sep 01 10:49:18 auth(default): Info: client in: AUTH    10     
DIGEST-MD5      service=pop3    lip=195.41.131.35      
rip=111.111.111.111       lport=110   rport=3730
Sep 01 10:49:18 auth(default): Info: digest-md5(?,111.111.111.111):
Invalid realm: example.com
Sep 01 10:49:25 auth(default): Info: client in: AUTH    11      PLAIN  
service=pop3    lip=195.41.131.35       rip=111.111.111.111      
lport=110       rport=3730   resp=<hidden>

Basically there is a lag of ~7-9 seconds upon login, this seems to be
consistant across the servers.

Any help would be greatly appreciated.

// Tom