[eluser]premedios[/eluser]
I got it working. I had to put .htaccess in the root folder of the installation. In my case was in the "blog" directory. This is my .htaccess contents:
RewriteEngine on
RewriteCond $1 !^(index\.php|images|robots\.txt)
RewriteRule ^(.*)$ /blog/index.php/$1 [L]