[exim] Custom Router/Transport Help

I'm trying to make a test mail server that is authorative for all domains
and delivers all mail received to one mailbox. I'm using debian 3, exim4
and courier imap.

I've added the router and transport below. I would like all mail delivered
into the sw user's mailbox. But i get permission errors upon delivery:

2010-03-01 18:17:27 1NmHfr-0003Pz-2n <=
root@???=root P=local S=443
2010-03-01 18:17:27 1NmHfr-0003Pz-2n ==
root@???=sw_router T=sw_deliver defer
(13): Permission denied: cannot chdir to
/home/sw/Maildir


What am i missing? Sorry i'm pretty new to exim configuration and developed
this config based on the delivered configuration.

router:

accept_all:
driver = accept
transport = just_deliver


Transport:

just_deliver:
debug_print = "T: maildir_home for $local_part@$domain"
driver = appendfile
.ifdef MAILDIR_HOME_MAILDIR_LOCATION
directory = MAILDIR_HOME_MAILDIR_LOCATION
.else
directory = /home/sw/Maildir
.endif
.ifdef MAILDIR_HOME_CREATE_DIRECTORY
create_directory
.endif
.ifdef MAILDIR_HOME_CREATE_FILE
create_file = MAILDIR_HOME_CREATE_FILE
.endif
delivery_date_add
envelope_to_add
return_path_add
maildir_format
.ifdef MAILDIR_HOME_DIRECTORY_MODE
directory_mode = MAILDIR_HOME_DIRECTORY_MODE
.else
directory_mode = 0700
.endif
.ifdef MAILDIR_HOME_MODE
mode = MAILDIR_HOME_MODE
.else
mode = 0600
.endif
mode_fail_narrower = false
# This transport always chdirs to $home before trying to deliver. If
# $home is not accessible, this chdir fails and prevents delivery.
# If you are in a setup where home directories might not be
# accessible, uncomment the current_directory line below.
current_directory = /