Ubuntu Servers :: Ssh Logout Cause 403 Forbidden Errors

i have strange problem on my wordpress-powered blog.while i'm connecting to server by ssh or physical console, everything works fine.however, when i tries to logout almost immediately 403 forbidden error pops up on every pages of my website.if there are two or more connections (like physical console and ssh terminal), terminate one of them does not cause 403 forbidden. but it shows 403 forbidden error page right after i terminated all connections.i can find two types of error in apache error.log while it shows 403 forbidden page.

Code:

(13)Permission denied: access to / denied

Code:

(13)Permission denied: /home/user/.htaccess pcfg_openfile: unable to check htaccess file, ensure it is readable(one strange part is my DocumentRoot is /home/user/www not /home/user)i gave 755 permission to all files and directories in DocumentRoot(which is /home/user/www), but still apache show me the forbidden error page right after logout.i use ubuntu 10.04 lts and i use apt-get command to install all package that i'm using now (apache,mysql,php,mrtg,snmpd,vsftpd,ssh,etc).these are my virtual host config file and apache2.conf. (httpd.conf is empty)

Code:

<VirtualHost *:80>
DocumentRoot /home/user/www/
<Directory /home/user/www/>

[code].....