Wp 3.1 MultiSite "Warning: realpath()" Problem

I hello
Before writing this post I looked on Google and in the www.remarpro.com forums and special sites and not gotten any answer that work for me.

The Problem:
Well, the main problem is simple, my Uploads not work in “non main site” for example… in https://www.mysite.com/om/ when i upload any file (like images) I recive the error below, so… in the main site and network (www.mysite.com/) all work fine…

The Error ??
Warning: realpath() [function.realpath]: Unable to access /var/www/vhosts/munipachalum.net/httpdocs/wp-admin/wp-content/uploads/2011/om/ in /var/www/vhosts/munipachalum.net/httpdocs/wp-includes/functions.php on line 2081

I did everything like…

• create a new blogs.dir directory and fix the permisions to 777 to the subfolders to
• I re check the .htacces file (see the my oter includes)
• also i check the config.php file
• I try change the values in my Data Base tables for the especific site (wp_2_options > fileupload_url and upload_path)
• In the Network site I edit the site info and change the values for the uploads path
• read and read forums and sites and some friends
• yes… of course, I been download a new copy of wp adn reinstalled (again)

Sooo… i do maybe any oter things but… nothing work or made some changes in the main site ( for now works fine) and this destroy the functionality

The truth It was I don’t really know where is the problem…

Some More Info
I have soooo sooo much files in the actual wp-content/uploads/ folder and many more entries and pages in the main blog

This is the content of my wp-config.php

define('WP_DEBUG', false);

define('WP_ALLOW_MULTISITE', true);

define( 'MULTISITE', true );
define( 'SUBDOMAIN_INSTALL', false );
$base = '/';
define( 'DOMAIN_CURRENT_SITE', 'munipachalum.net' );
define( 'PATH_CURRENT_SITE', '/' );
define( 'SITE_ID_CURRENT_SITE', 1 );
define( 'BLOG_ID_CURRENT_SITE', 1 );

And this is the code of my .htaccess file

RewriteEngine On
RewriteBase /
RewriteRule ^index\.php$ - [L]

# uploaded files
RewriteRule ^([_0-9a-zA-Z-]+/)?files/(.+) wp-includes/ms-files.php?file=$2 [L]

# add a trailing slash to /wp-admin

RewriteRule ^([_0-9a-zA-Z-]+/)?wp-admin$ $1wp-admin/ [R=301,L]

RewriteCond %{REQUEST_FILENAME} -f [OR]
RewriteCond %{REQUEST_FILENAME} -d
RewriteRule ^ - [L]
RewriteRule  ^[_0-9a-zA-Z-]+/(wp-(content|admin|includes).*) $1 [L]
RewriteRule  ^[_0-9a-zA-Z-]+/(.*\.php)$ $1 [L]
RewriteRule . index.php [L]

Please so sorry for my bad English, I speak Spanish

I realy need resolve that, this is my frist profesional project with multi-site’s

sooo Tnks a lot ??