[Kroupware] New account IMAP error

[will]

Hi all,

We have Kolab Server Version 1.0 installed here at work, and it has been 
running fine, except we have a slight problem creating new accounts.  I 
have created about 20 accounts sucessfully, but now if I create a new 
account and then try and configure an IMAP client I get the error "Mail 
box does not exist":

http://home.hellacool.co.uk/Screenshot.png

The user gets created in LDAP sucessfully, and they appear in the users 
section of teh web based interface, but it is not possiblt to log in to 
the mail account (or send mail to that new account).  All existing users 
are working fine.

Does anyone have any ideas why I am getting this error, and what I can 
do to fix this?

Many thanks
Will.