Redmine

Greetings everyone,

I am trying to figure out how to serve redmine from a sub-directory from apache2 + passenger. I managed to install everything including redmine in Ubuntu 13.04, and can serve from 192.168.1.2 normally, however when I try to serve from a sub-directory (192.168.1.2/redmine) I get 403 forbidden error. I am trying to run redmine in sub directory like done by bitnami folks AFAICT it's possible to serve without proxy nor linking to www directory but I can't figure it out.
My actual config files are :
sites-available/default

<VirtualHost *:80>
        ServerAdmin webmaster@localhost

        DocumentRoot /var/www
        <Directory />
                Options FollowSymLinks
                AllowOverride None
        </Directory>
        <Directory /var/www/>
                Options Indexes FollowSymLinks MultiViews
                AllowOverride None
                Order allow,deny
                allow from all
        </Directory>

        ScriptAlias /cgi-bin/ /usr/lib/cgi-bin/
        <Directory "/usr/lib/cgi-bin">
                AllowOverride None
                Options +ExecCGI -MultiViews +SymLinksIfOwnerMatch
                Order allow,deny
                Allow from all
        </Directory>

        ErrorLog ${APACHE_LOG_DIR}/error.log

        # Possible values include: debug, info, notice, warn, error, crit,
        # alert, emerg.
        LogLevel warn

        CustomLog ${APACHE_LOG_DIR}/access.log combined
</VirtualHost>
<VirtualHost *:8888>

        DocumentRoot /usr/local/share/redmine-2.3.3/public
        <Directory /usr/local/share/redmine-2.3.3/public>
                AllowOverride all
                Options -MultiViews
        </Directory>
</VirtualHost>

Alias /redmine "/usr/local/share/redmine-2.3.3/public" 

RailsBaseURI /usr/local/share/redmine-2.3.3
<Directory /usr/local/share/redmine-2.3.3/public>
        PassengerEnabled on
        AllowOverride all
        Options -MultiViews
        Order allow,deny
        Allow from all
</Directory>
PassengerPreStart http://127.0.0.1:80/redmine

<IfModule mod_passenger.c>
  PassengerDefaultUser www-data
  PassengerRoot /usr
  PassengerRuby /usr/bin/ruby
</IfModule>

LoadModule passenger_module /usr/lib/apache2/modules/mod_passenger.so

As you can see from default config file, I set up access to redmine on port 8888 with direct access and set up same instance as sub directory on port 80, I can access 192.168.1.2:8888's but can't access 192.168.1.2/redmine
Maybe it's possible to achieve the result using proxy directive or symlinking to www directory, but I would like to do it the direct way.

Thank's in advance.

Najib.