When editing a NODE in a colorbox and validation fail, a File Download Dialog show up ???

Yea its possible, you just need to change the node edit form to be ajax. You will need to perform a form_alter to make that happen. You can look in the .module file and see how I did that for webforms and just follow suit.

It would be great if you can provide a drupal patch so the maintainer can work on it easily. Anyways I will test your patch see if I can create one.

Thanks for your information. I hope it works even with image uploads in the node edit forms in colorbox.

There is help topics on this that explain step by step.
Besides that, I'm not sure I want to start supporting edit forms, that's what overlay is for and is more stable than using colorbox.

Hi iLLin,

Can you link to where these help topics are? It seems like there is a lot of help out there, until you want to do a modal node/add and then the crickets start chirping.

I even tried the changes proposed by bnetsolutioninc, but it does not seem to work for me. I've tried everything out there that I can find. Admin overlay completely jacks up my theming. I'm down to CTools Auto-Modal and this article:
http://pixeljets.com/blog/improving-user-experience-using-dialogs-profil...

Is there something I'm missing?

You need to ajaxify your node edit form. So when you call it into the colorbox node modal, it will stay in screen. Then you need to manually manage your redirect when they submit (maybe, it might just work). This is all custom MD3, you get crickets because of that. Look at this module in the webform form alter section. That will show you how to ajaxify a form. There is lots of help topics on how to make your form ajax. Maybe you just don't have the right keywords in your search? Here is what I searched for in google "drupal 7 ajax form" here is the first thread that comes up http://drupal.org/node/752056 . Pretty good help page eh?

In case someone ends up here and needs a quick solution, here it is:

/**
 * Implements hook_form_alter();
 */
function mymodule_form_alter(&$form, &$form_state, $form_id) {
  switch ($form_id) {
    case 'event_node_form' :
      $form['actions']['submit']['#ajax'] = array(
        'callback' => 'mymodule_form_js_submit',
        'wrapper' => 'event-node-form',
        'method' => 'replace',
        'effect' => 'fade',
      );
      break;
  }
}

function mymodule_form_js_submit($form, $form_state) {
  $sid = $form_state['values']['details']['sid'];
  if (!$sid) {
    return $form;
  }
}

Here is a better submit handler.

function MODULE_NAME_js_submit($form, &$form_state) {
  if (!form_get_errors()) {
     // maybe a redirect or some javascript to close the window
  } else {
    return $form;
  }
}

Patch to try out #2468797: Ajaxify core forms (User/Node/Login/Registration)