vexim not creating local delivery folders

Dear List members

I have installed vexim as per the instructions. The only difference is
that I have made my uid and gid similar to sendmail/exim -- i.e., uid is
mailnull and gid is mail. I have made the same changes in variables.php

However, as I am trying to create a local domain, the delivery directory
is not being created. I have set the local delivery top level folder to
be /Vexim/LocalDelivery/ and it is being owned by mailnull and mail.
Still, as I create a new local folder, even though the database is
updated accordingly, the folders are not being created. But nothing is
registered in apache or message logs.

I am using FreeBSD 7 stable, apache 22 and php5, and I have php5-posix
installed (as suggested in some site I can't remember).

Would appreciate any pointer/suggestion to resolve this matter. If any
other information is required, please let me know and I'll try to post
them accordingly.

Thank you.