gnutls-cli works but wl hangs

[mike@mikedeplume.com]

Hi,

I'm trying to get wl to attach to an imap server. The server uses tls, with 
plain authentication. I'm running Ubuntu, with emacs 22 and either wl 2.14.10 
or wl 2.15.6 (package wl-beta). Both packages show the same problem.

The folder definition looks something like:

%remote_folder:"my.name@example.com"/plain@imap.example.com:993!!

When I start wl it goes through the folders and reaches %remote_folder. I see 
the message:

Opening STARTTLS connection to `imap.example.com'...done

and the emacs window hangs. I do _not_ get a password prompt, and there is no 
password for this server in the password file (so I would expect a prompt).

In the process list I see:

/usr/bin/gnutls-cli -s imap.example.com -p 993

When I kill this process the emacs window wakes up and complains "Cannot open: 
elmo-network-initialize-session", which is to be expected.

If I copy the gnutls-cli command from process list and try it on the command 
line it connects just fine and I can log in to the server using the username 
from the .folders file (and the correct password, of course).

If I set imap debug I do _not_ get any debug messages. (The debug buffer does 
not appear).

My conclusion so far - The server name is correct, the server supports tls, 
gnutls does not throw a verification error for the server certificate, and my 
user name is correct.

I am guessing that the fact I don't get a password prompt is significant.

I am now at a loss as to what to do next. Has anyone seen this before? Has 
anyone got any ideas what to try?

Cheers

Mike S.