Nicedit upload images locally fails

Question

This is how I call the editor:

new nicEditor({
           buttonList : ['bold','italic','underline','upload'],
           iconsPath:'img/nicedit.png',
           uploadURI : 'http://server.com/integracion/files/nicUpload.php'
}).panelInstance(textareaId);

And the .php file exists ( and I the one in the Docs, and I updated the target paths )

/* I want them here http://server.com/integracion/files/uploads/ so... */   
    define('NICUPLOAD_PATH', './uploads'); // Set the path (relative or absolute) to
                                              // the directory to save image files                  
    define('NICUPLOAD_URI', '/uploads');   // Set the URL (relative or absolute) to
                                              // the directory defined above

But I on response when upload completes (and of corse an alert from nicedit..)

<script>
        try {
            top.nicUploadButton.statusCb({"error":"Invalid Upload ID"});
        } catch(e) { alert(e.message); }
    </script>

what am I missing?

-EDIT

I think the problem might be in the php file:

$id = $_POST['APC_UPLOAD_PROGRESS'];  /* APC is installed and enabled */
if(empty($id)) {
    $id = $_GET['id'];
}

Answer 1

FINAL EDIT:

I have managed to make this work!

Here is an working example:
http://simplestudio.rs/yard/nicedit/

Uploaded images are going to be stored here:
http://simplestudio.rs/yard/nicedit/images/

And here is the whole code, just unpack it and put on your server, mainly I needed to adjust nicEdit.js because it had some issues.
http://simplestudio.rs/yard/nicedit/nicedit.rar

Just make your code with that js file and by looking at my example, it will work :)

• Also you need to have php APC installed so that this script can work:
  http://php.net/manual/en/apc.installation.php

If you by any mean have some problems I am here to solve it.

• I will not delete this example on my server so that everybody who have this issue can freely download it...