Using FakeObjects with non HTML tags

I'm trying to figure out how to insert an non HTML tag into the editor with a placeholder image. I was able to do the initial insert without any issues. However, whenever I switch to source and back or when the editor loads with the non HTML tag already in it, the placeholder image doesn't show.

I looked at the flash and link plugins to get an idea of how it should work, but even replicating it exactly is not working. The first tag I am trying to create is called cf_displayfeed. The code of the plugin is below:

CKEDITOR.plugins.add('cf_displayfeed',{
    requires: ['fakeobjects' ],
    init:function(a){
         a.addCss(
            'img.cke_cf_displayfeed' +
            '{' +
               'background-image: url(' + CKEDITOR.getUrl( this.path + 'images/AddCatalogItem.gif' ) + ');' +
               'background-position: center center;' +
               'background-repeat: no-repeat;' +
               'border: 1px solid #a9a9a9;' +
               'width: 40px;' +
               'height: 40px;' +
            '}'
            );
        var cmd = a.addCommand('cf_displayfeed', {exec:catalog_onclick})
        //cmd.modes={wysiwyg:1}
        cmd.canUndo=false
        a.ui.addButton('cf_displayfeed',{ label:'Insert Catalog Link', command:'cf_displayfeed', icon:this.path+'images/AddCatalogItem.gif' })
    },
      afterInit : function( editor )
      {
         var dataProcessor = editor.dataProcessor,
            dataFilter = dataProcessor && dataProcessor.dataFilter;

         if ( dataFilter )
         {
            dataFilter.addRules(
               {
                  elements :
                  {
                     'cke:cf_displayfeed' : function( element )
                     {
                        return editor.createFakeParserElement( element, 'cke_cf_displayfeed', 'cf_displayfeed', false);
                     }
                  }
               },
               5);
         }
      }
})


function catalog_onclick(e)
{
   window.open('/Components/CatalogLinks.cfm?Action=Add',"","HEIGHT=600,WIDTH=800,left=50,top=50, scrollbars,menubar,alwaysraised,resizable=1");
}

Anyone have an idea of why this may not be working? I'm assuming the issue is specifically because of the non HTML tag.

Thanks