Normalíssimo.
Confirme que o usuário que roda o apache tem acesso ao diretório de instalação do magento.
Fale Grande, o root é o usuário do apache... segue
root@linux:/home/vitor# ls -l /etc/apache2/
total 72
-rw-r--r-- 1 root root 7994 2011-09-01 06:25 apache2.conf
drwxr-xr-x 2 root root 4096 2011-10-31 16:38 conf.d
-rw-r--r-- 1 root root 1169 2011-09-01 06:25 envvars
-rw-r--r-- 1 root root 78 2011-11-01 15:54 httpd.conf
-rw-r--r-- 1 root root 31063 2011-09-01 06:25 magic
drwxr-xr-x 2 root root 4096 2011-11-01 11:41 mods-available
drwxr-xr-x 2 root root 4096 2011-10-31 11:18 mods-enabled
-rw-r--r-- 1 root root 750 2011-09-01 06:25 ports.conf
drwxr-xr-x 2 root root 4096 2011-10-31 11:04 sites-available
drwxr-xr-x 2 root root 4096 2011-10-31 11:04 sites-enabled
E o meu usuário (Vitor) aparece nos permissões do magento
root@linux:/home/vitor# ls -l /var/www/magento/
total 540
drwxrwxrwx 6 vitor vitor 4096 2011-09-29 15:06 app
-rwxr-xr-x 1 vitor vitor 1606 2009-04-30 17:13 cron.php
-rwxr-xr-x 1 vitor vitor 642 2010-02-17 15:54 cron.sh
drwxr-xr-x 7 vitor vitor 4096 2011-09-29 15:06 downloader
drwxr-xr-x 3 vitor vitor 4096 2011-11-02 00:36 errors
-rwxr-xr-x 1 vitor vitor 1150 2008-03-06 06:22 favicon.ico
-rwxr-xr-x 1 vitor vitor 5979 2011-08-17 14:40 get.php
drwxr-xr-x 2 vitor vitor 4096 2011-09-29 15:07 includes
-rwxr-xr-x 1 vitor vitor 2571 2010-03-03 20:09 index.php
-rwxr-xr-x 1 vitor vitor 2366 2009-10-07 11:37 index.php.sample
-rwxr-xr-x 1 vitor vitor 6367 2010-09-28 11:56 install.php
drwxr-xr-x 12 vitor vitor 4096 2011-09-29 15:07 js
drwxr-xr-x 11 vitor vitor 4096 2011-09-29 15:07 lib
-rwxr-xr-x 1 vitor vitor 10421 2008-10-31 22:51 LICENSE_AFL.txt
-rwxr-xr-x 1 vitor vitor 10679 2009-04-13 13:26 LICENSE.html
-rwxr-xr-x 1 vitor vitor 10410 2007-09-27 18:12 LICENSE.txt
-rwxr-xr-x 1 vitor vitor 1319 2010-07-19 18:07 mage
drwxrwxrwx 6 vitor vitor 4096 2011-09-29 15:06 media
-rwxr-xr-x 1 vitor vitor 751 2008-08-02 00:02 php.ini.sample
drwxr-xr-x 2 vitor vitor 4096 2011-09-29 15:08 pkginfo
-rwxr-xr-x 1 vitor vitor 422349 2011-09-29 12:14 RELEASE_NOTES.txt
drwxr-xr-x 2 vitor vitor 4096 2011-09-29 15:07 shell
drwxr-xr-x 5 vitor vitor 4096 2011-09-29 15:06 skin
drwxrwxrwx 7 vitor vitor 4096 2011-11-02 00:27 var
Como que eu mudo de usuário o diretório do magento ?
Atencisoamente!!