IMAP <-> IMAP issues..

Here's the scenario so you know what's going on:
I'm migrating from M$ Exchange to Courier-imap on a Debian 3.0r1
stable/unstable hybrid box.  I will be having my users connect to their
IMAP mailboxes through Mozilla Thunderbird or a webmail client (such as
Squirrelmail).

Offlineimap is the only program I've found so far that will reliably
read the IMAP folders from my Exchange 5.5 server.  It seems to read
them and download them quite quickly and effectively to a local Maildir
folder.  However, the Maildir folder that Offlineimap creates does not
have the '.' in front of the folder name for Courier-imap to recognize
it as a folder for it to subscribe to.  Nor does Offlineimap subscribe
to the folder.

In the interest of trying to get this to work, I tried setting up
IMAP<->IMAP instead.  However it does not seem to function as expected.
I've checked the perms on my Maildir folder, it *was* set to 700, so as
a test, I set it to 777, I still received the same error message.

Help!

Here is the error message I receive:
-----
Thread 'Account sync Test' terminated with exception:
Traceback (most recent call last):
  File "/usr/lib/python2.3/site-packages/offlineimap/threadutil.py",
line 153, in run
    Thread.run(self)
  File "/usr/lib/python2.3/threading.py", line 422, in run
    self.__target(*self.__args, **self.__kwargs)