Problems running IMAP over ssh port forwarding

[Steinar Bang <sb@dod.no>]

Platform: Windows 7,
          GNU Emacs 24.4.1 (i686-pc-mingw32) of 2014-10-24 on LEG570
          Ma Gnus v0.16 (last standalone git version)

I tried setting up a port forwarding like so:
  ssh -L 143:localhost:143 mysever.mydomain

I then tried setting the IMAP server like this:
(setq gnus-secondary-select-methods
      '((nnimap "privat"
		(nnimap-address "localhost")
                (nnimap-authenticator cram-md5)
                (nnimap-server-port 143))
	))

However this doesn't work.  In the " *nnimap localhost 143 **nntpd*"
buffer, I saw the following (replaced CR with explicit "^M" to be able
to send it in this message):
[CAPABILITY IMAP4rev1 LITERAL+ SASL-IR LOGIN-REFERRALS ID ENABLE IDLE STARTTLS AUTH=PLAIN AUTH=CRAM-MD5] Dovecot ready.^M
 BAD CR sent without LF^M
* BAD Error in IMAP command received by server.^M
* BAD Error in IMAP command received by server.^M
* BYE Too many invalid IMAP commands.^M

Process *nnimap* connection broken by remote peer

Does anyone have an idea what could be wrong here?

Thanks!


- Steinar