[Dovecot] Problems with dovecot deliver.

[Dpoke]

Hello all.

I am using dovecot 1.1.rc4.

Some of my mail deliver without errors. Other mail during its deliver 
give next errors in logs:

Postfix log

Jun 16 18:34:17 postfix/local[2730]: A394E292002: 
to=<dpoke at localhost.mail.com>, orig_to=<dpoke at localhost>, relay=local, 
delay=3013, delays=3008/1.3/0/2.9, dsn=4.3.0, status=deferred (temporary 
failure)
Jun 16 18:34:17 postfix/local[2731]: B5FE7292004: 
to=<dpoke at localhost.mail.com>, orig_to=<dpoke at localhost>, relay=local, 
delay=2998, delays=2994/0.98/0/2.6, dsn=4.3.0, status=deferred 
(temporary failure)
Jun 16 18:34:18 postfix/local[2731]: 28723292003: 
to=<dpoke at localhost.mail.com>, orig_to=<dpoke at localhost>, relay=local, 
delay=2993, delays=2989/3.5/0/0.72, dsn=4.3.0, status=deferred 
(temporary failure)
................................................

Deliver log. (Also I found no other useful information relaying this 
problem in other dovecot logs.)

deliver(dpoke): Jun 16 18:34:15 Info: maildir: data=/opt/home/dpoke//Maildir
deliver(dpoke): Jun 16 18:34:15 Info: maildir++: 
root=/opt/home/dpoke//Maildir, index=, control=, 
inbox=/opt/home/dpoke//Maildir
deliver(dpoke): Jun 16 18:34:15 Info: maildir: data=/opt/home/dpoke//Maildir
deliver(dpoke): Jun 16 18:34:15 Info: maildir++: 
root=/opt/home/dpoke//Maildir, index=, control=, 
inbox=/opt/home/dpoke//Maildir
deliver(dpoke): Jun 16 18:34:16 Error: 
open(/tmp/dovecot.deliver..1213626856.2732.ad657cfa5dccbc61) failed: 
Permission denied
deliver(dpoke): Jun 16 18:34:16 Error: copy: i_stream_read() failed: 
Permission denied
deliver(dpoke): Jun 16 18:34:16 Info: msgid=: save failed to INBOX: 
Internal error occurred. Refer to server log for more information. 
[2008-06-16 18:34:14]
deliver(dpoke): Jun 16 18:34:16 Error: 
open(/tmp/dovecot.deliver..1213626856.2733.ad657cfa5dccbc61) failed: 
Permission denied
deliver(dpoke): Jun 16 18:34:16 Error: copy: i_stream_read() failed: 
Permission denied
deliver(dpoke): Jun 16 18:34:16 Info: msgid=: save failed to INBOX: 
Internal error occurred. Refer to server log for more information. 
[2008-06-16 18:34:14]
deliver(dpoke): Jun 16 18:34:17 Info: maildir: data=/opt/home/dpoke//Maildir
deliver(dpoke): Jun 16 18:34:17 Info: maildir++: 
root=/opt/home/dpoke//Maildir, index=, control=, 
inbox=/opt/home/dpoke//Maildir
deliver(dpoke): Jun 16 18:34:17 Info: maildir: data=/opt/home/dpoke//Maildir
deliver(dpoke): Jun 16 18:34:17 Info: maildir++: 
root=/opt/home/dpoke//Maildir, index=, control=, 
inbox=/opt/home/dpoke//Maildir
deliver(dpoke): Jun 16 18:34:17 Error: 
open(/tmp/dovecot.deliver..1213626857.2737.712b51aaca368d64) failed: 
Permission denied
deliver(dpoke): Jun 16 18:34:17 Error: copy: i_stream_read() failed: 
Permission denied
deliver(dpoke): Jun 16 18:34:17 Info: msgid=: save failed to INBOX: 
Internal error occurred. Refer to server log for more information. 
[2008-06-16 18:34:17]
deliver(dpoke): Jun 16 18:34:17 Error: 
open(/tmp/dovecot.deliver..1213626857.2736.712b51aaca368d64) failed: 
Permission denied
deliver(dpoke): Jun 16 18:34:18 Error: copy: i_stream_read() failed: 
Permission denied
deliver(dpoke): Jun 16 18:34:18 Info: msgid=: save failed to INBOX: 
Internal error occurred. Refer to server log for more information. 
[2008-06-16 18:34:17]
.....................................................

This is my dovecot configuration:

# 1.0.3: /opt/etc/dovecot.conf
protocols: imap
listen: 192.168.1.1
ssl_disable: yes
disable_plaintext_auth: no
login_dir: /opt/var/run/dovecot/login
login_executable: /opt/libexec/dovecot/imap-login
login_user: nobody
login_processes_count: 1
auth default:
  verbose: yes
  debug: yes
  passdb:
    driver: passwd-file
    args: /opt/etc/passwd.imap
  userdb:
    driver: passwd-file
    args: /etc/passwd

How can I fix this mail delivering problem?

Thanks in advance for any ideas/suggestions/answers.
And sorry for my bad English ;)

-- Ilya Galanin