Thank you... You save my ass :D

Yes, I used an explicit z-index setting to workaround this.

.cke_skin_kama .cke_dialog_body { z-index: 10200 !important; }

Najlos, I have a problem with showing a plupload in a jquery UI modal windows, same as you, but can´t fix it. what you did to fix it ?, thanks !!

HTML CODE

<div id="pupload-portlet-container" class="container" style="display:none">
    <div id="uploader_container">
        <div id="html4_uploader" style="width: 550px; height: 400px; display:none">HTML 4 support</div>
        <div id="html5_uploader" style="width: 550px; height: 400px; display:none">HTML5 support</div>
    </div>
</div>

JS CODE

function showDialgo(){
      jQuery("#pupload-portlet-container").show();
      $('#uploader_container').dialog({
                resizable: false,
                draggable: true,
                height: 450,
                width: 600,
                open: function(event, ui) {createFileUploaderHTML5();}}
            );
}

 function createFileUploaderHTML5(){
        $("#html5_uploader").show();
        $("#html5_uploader").plupload({
            runtimes : 'html5',
            url : fileUploadURL,
            max_file_size : maxFileSize,
            chunk_size : '1mb',
            unique_names : true,
            filters : [
                {title : "Image files", extensions : "jpg,gif,png"}           
            ],
            init:{
                FileUploaded:function(up,file,info){                       
                    publishResults(info);
                }
            }
        });    
    }

It works in IE, Safari, Chrome but not in FF...

Thanks