[solved]Force Drupal to attach Drupalbehavior to new ajaxed content [only Drupal.attachBehaviors() is not working the right way]

Hello to all drupal fans.
I was doing lot of posts about this topic, but unfortunately in the wrong context.
http://drupal.org/node/1125570
http://drupal.org/node/1114200

I think that is not the problem, so i try it with a different approach, and maybe this could be the solution.
Loading the whole PHP Page and extract a certain div with ajax didn't works the right way.
So i thought, that i could let drupal load just the content and inject it with ajax into the div.
I made a query with the hook_preprocess_page and hook_preprocess_node that is looking for a "ajax=1" in the requested URL and then only gives out the content without the whole page. And now with help of certain tpl.php files, in theory, i could limit the output of drupal to only $content. And here is the problem. My approach is working even when i leave the tpl.php files the original way, but removing the "$content" from node-ajax.tpl.php.
With "working the right way", i mean that drupal doesn't reload the whole page, but off course not the content.
But i can not explain that to myself, cause in the $content variable, so i thought, is only the html of the generated content.
So my question is, how can i limit the output of drupal, to just the content, or am i doing the wrong steps to get this working.
Here is the module and js file i'm using:
my_ajax.module:

<?php

function my_ajax_init() 
{
    drupal_add_js(drupal_get_path('module', 'my_ajax') . '/my_ajax.js');
}

function my_ajax_preprocess_page(&$vars, $hook) 
{
    
    if (isset($_GET['ajax']) && $_GET['ajax'] == 1) 
    {
        $vars['template_file'] = 'page-ajax';
    }
}

function my_ajax_preprocess_node(&$vars, $hook) 
{
    
    if (isset($_GET['ajax']) && $_GET['ajax'] == 1) 
    {
        $vars['template_file'] = 'node-ajax';
    }
}

my_ajax.js:

Drupal.behaviors.my_ajax = function (context) {
    $('#content-group-inner .node a').live('click', function (e) {
        var url = $(this).attr('href');
        //$('#content-region-inner').slideUp('slow');
        $('#content-region-inner').empty().html('<img src="ajax-loader.gif" style="margin-left:50%;"/>');
        xhr = $.ajax({
            data: 'ajax=1',
            type: 'GET',
            url: url,
            success: function (data) {
                $('#content-region-inner').html(data);
                Drupal.attachBehaviors(context);
            }
        });
        return false;
    });
};

Please help me with this.
Every suggestion is appreciated.