Can't display blog post list starting from post 4

Hello,

First, sorry for my bad english, I'm french.

On my blog's homepage I would like to feature the 3 latest blog posts with a special presentation, and the 7 others with a simple listing.

For the first 3 articles, I used this :

<?php
        perch_blog_custom(array(
        'sort' => 'postDateTime',
        'template' => 'post_in_list_recents.html',
        'sort-order' => 'DESC',
        'count' => 3,
    ));
?>

For the 7 others, I used this :

<?php  
        perch_blog_custom(array(
        'sort' => 'postDateTime',
        'template' => 'post_in_list.html',
                'sort-order' => 'DESC',
                'start' => 4,
                'count' => 7,
        ));
?>

But this display all the latest posts, not starting from 4. What am I doing wrong ?