CKEditor 4.3 breaks custom plugin (createFakeParserElement)

We have a 'customwidget' plugin that has been working perfectly.

I've updated to 4.3, to deal with IE11 issues. However the custom plugin we're using to insert a fake object is no longer working. I've tried cross referencing against the flash plugin which uses a similar approach but can't see any difference.

We can insert a fake element fine. We lose the fake 'widget' element when we:

• Go back and forth between 'view source'
• Save the contents, reload content back in

Here's the /plugins/customwidget/plugin.js:

(function()
{

	function createFakeElement( editor, realElement ) {
		return editor.createFakeParserElement( realElement, 'cke_widget', 'widget', true );
	}

	widgets = [];
	
    jQuery.ajax({
       type: "GET",
       dataType:'json',
       cache: false,
       url: "/websuite/secure/app/cms/manager/ajax/get-editor-widget-list.cfm",
       timeout: 3000,
       error: function() {      
            return false;
       },
       success: function(json) {
           widgets = json;
       }
    });
		
	CKEDITOR.plugins.add('customwidget',
	{
		icons: 'widget',
		onLoad: function() {
			CKEDITOR.addCss(
				'img.cke_widget' +
				'{' +
					'background-image: url(' + CKEDITOR.getUrl( this.path + 'images/placeholder.png' ) + ');' +
					'background-position: center center;' +
					'background-repeat: no-repeat;' +
					'width: 16px;' +
					'height: 16px;' +
				'}'
			);
		},
	    init: function(editor)
	    {
	        var pluginName = 'customwidget';
	        CKEDITOR.dialog.add(pluginName, this.path + 'dialogs/widget.js');
	        editor.addCommand(pluginName, new CKEDITOR.dialogCommand(pluginName));
	        editor.ui.addButton(
	        	'Widget',
	            {
	                label: 'Widget',
	                command: pluginName
	            }
	        );
	    },
		afterInit : function ( editor )
		{
		
			var dataProcessor = editor.dataProcessor,
				dataFilter = dataProcessor && dataProcessor.dataFilter;
				
			if ( dataFilter )
			{
				dataFilter.addRules(
					{
						elements :
						{
							'widget' : function( element )
							{
								return createFakeElement( editor, element );
							}
						}
					}, 5);
			}
			
			
		},
		requires: 'fakeobjects'	    
	});
	
})();  

And here's the /plugins/customwidget/dialogs/widget.js

( function(){
	
	CKEDITOR.dialog.add('customwidget', function(editor) {
		return {
			title : 'Insert Widget',
			minWidth : 400,
			minHeight : 50,
			onOk: function() {
				var dialog = this, data = {}, customwidget = editor.document.createElement( 'widget' );
				this.commitContent( data );
 				customwidget.setAttribute( 'id', data.id );
 				customwidget.setAttribute( 'title', data.title );
				var newFakeImage = editor.createFakeElement( customwidget, 'cke_widget', 'widget', true );
				$(newFakeImage).attr('title',data.title);
				$(newFakeImage).attr('alt',data.title);
				editor.insertElement( newFakeImage );
			},
			contents: [{
		        id: 'choose',
		        label: 'Choose',
		        elements: [{
			        type: 'select',
			        id: 'id',
			        label: 'Choose a widget',
			        labelLayout: 'horizontal',
			        items: widgets,
	        		commit : function( data )
					{
						data.id = this.getValue();
						
						// TODO: this could be more elegant
						data.title = $('#'+this.getDialog().getContentElement('choose','id').domId+' select').find(":selected").text();
					}
                }]
		    }]
		};
	});
		
})();

I've tried renaming to widget2 in places, just in case the new widget fuctionality is conflicting but no joy. No errors are returned. Just seems the dataFilter is no longer being respected.

Any ideas? Thanks in advance.