Unable_to_open_./Maildir:_is_a_directory._(#4.2.1)/

[Essy Ren]

Hello again
I've installed qmail-1.03 and using bind 9
I've made the MX record like this in my db.test.local file :
    mail                    IN      MX    10 riga.test.local
    mail                    IN      A     192.168.1.31


When I run the ps aux the qmail seems to run :
    qmails     134  0.0  0.3  1088  392 ?        S    09:51   0:00
qmail-send
    qmaill     139  0.1  0.2  1052  364 ?        S    09:51   0:00
/usr/local/bin/multilog t /var/log/qmail/smtpd
    qmaill     141  0.0  0.2  1044  336 ?        S    09:51   0:00
/usr/local/bin/multilog t /var/log/qmail
    root       142  0.0  0.2  1048  336 ?        S    09:51   0:00
qmail-lspawn ./Maildir
    qmailr     143  0.0  0.2  1048  328 ?        S    09:51   0:00
qmail-rspawn
    qmailq     144  0.0  0.2  1040  348 ?        S    09:51   0:00
qmail-clean

But when I try to send myself an email, it show line like this at my
/var/log/qmail/current file :
    @400000003b4528aa0eba06f4 starting delivery 4: msg 191485 to local
[EMAIL PROTECTED]
    @400000003b4528aa0eba7c24 status: local 1/10 remote 0/20
    @400000003b4528aa1125658c delivery 4: deferral:
Unable_to_open_./Maildir:_is_a_directory._(#4.2.1)/
    @400000003b4528aa1125e674 status: local 0/10 remote 0/20

eventhough i set the mode to 777 at my Maildir, it didn't take any effect
...
can someone help me ... ?
thanks