High CPU when logging in

Good day,

I was using MIMP with CVS versions of Horde some number of months ago with
success.  My MIMP installation broke after an update but I didn't worry
about it too much since the code wasn't even alpha yet.

I realize that MIMP is now in alpha status, but I thought I'd install it
nonetheless on my production Horde 3.0.5 install (Windows 2000 with PHP
v4.3.11).  Turns out I'm getting the same problem - the login screen will
come up, but when I press the "Log in" button the web server shoots up to
100% CPU and I never get a folder/message list.  However if I enter the
wrong credentials I'll get a message telling me that the login failed.

I suspect this has to do with IMAP and folders and such.  My servers.php
file consists of:

$servers['imap'] = array(
    'name' => 'IMAP mail',
    'server' => 'localhost',
    'hordeauth' => false,
    'protocol' => 'imap/notls',
    'port' => 143,
    'maildomain' => '',
    'realm' => '',
);

Might anybody have some insight?

Thanks, and Happy New Year!