[Dovecot] BUG: Authentication client sent unknown handshake command

[Emmanuel Dreyfus]

Hi

After upgrading the kernel, everything is fine, except dovecot authentication.
I get this trange thing (data after REQUEST? changed just in case it 
contains anything sensitive):

Nov 29 16:56:01 volanges dovecot: auth: Error: BUG: Authentication client sent unknown handshake command: REQUEST?6970356762?616?6?235264ef69dbd1665538af54d12fdaea?session_pid=453?req...
Nov 29 16:56:01 volanges dovecot: imap: Error: Authentication server didn't send valid SPID as expected: MECH   PLAIN   plaintext
Nov 29 16:56:01 volanges dovecot: imap: Error: Disconnected from auth server, aborting (client-pid=161 client-id=1)
Nov 29 16:56:01 volanges dovecot: imap-login: Internal login failure (pid=161 id=1) (internal failure, 1 successful auths): user=<jdoe>, method=PLAIN, rip=192.0.2.251, lip=192.0.2.10, mpid=453, TLS, TLSv1 with cipher AES128-SHA (128/128 bits)

Reverting to the previous kernel fixed the problem, but I have not been 
able to spot what the problem was. Any idea?

-- 
Emmanuel Dreyfus
manu at netbsd.org