TreeGrid with XJSONDataSource - Script warning

[ADA]

Hi,
I am trying to build a TreeGrid populating with the 'Title' field for the first level from YAHOO! JSON Services http://api.search.yahoo.com/ImageSearchService/V1/imageSearch?appid=YahooDemo&output=json

I am trying with the Yahoo! JSON Services example under Data Integration from the SmartGWT Showcase. I am just replacing the ListGrid show in the example with a TreeGrid. The tree shows "Loading data.." , and a window with the message "Finding records that match your criteria..." then Getting a Script warning.

Script warning from GWT -
"A script on this page is causing mozilla to run slowly. If it continues to run, your computer may become unresponsive. Do you want to abort the script?"

Script warning from a Standalone browser -
"Warning: Unresponsive script. A script on this page may be busy, or it may have stopped responding." Along with a random script like

Script: http://localhost:8888/com.mycompany.Campaign/sc/client/language/Tree.js:905
or
Script: http://localhost:8888/com.mycompany.Campaign/sc/client/language/Array.js:132
or
Script: http://localhost:8888/com.mycompany.Campaign/sc/client/language/Array.js:772
or
Script: http://localhost:8888/com.mycompany.Campaign/sc/client/language/IsA.js:173

Can anyone please let me know what I am missing here or point me to any sample code.
I am using SmartGWT 1.0 b2 and GWT 1.5.3 for linux.
Thanks in advance for any help.

Following is the code

 XJSONDataSource xjsonDS = new XJSONDataSource();
 xjsonDS.setDataURL("http://api.search.yahoo.com/ImageSearchService/V1/imageSearch?appid=YahooDemo&output=json");
 xjsonDS.setRecordXPath("/ResultSet/Result");
    
 DataSourceIntegerField pkField = new DataSourceIntegerField("pk");
 pkField.setHidden(true);
 pkField.setPrimaryKey(true);
    
 DataSourceTextField title = new DataSourceTextField("Title");
 title.setRootValue("1");
    
 xjsonDS.addField(pkField);
 xjsonDS.addField(title);

   
 final TreeGrid jsonTree = new TreeGrid();
 jsonTree.setLoadDataOnDemand(false); 
 jsonTree.setTop(100);
 jsonTree.setWidth("30%");
 jsonTree.setHeight("60%");
 jsonTree.setShowConnectors(true);       
 jsonTree.setNodeIcon("icons/16/folder_document.png");
 jsonTree.setFolderIcon("icons/16/folder_out.png");
 jsonTree.setShowOpenIcons(false);
 jsonTree.setShowDropIcons(false);
 jsonTree.setClosedIconSuffix("");     
 jsonTree.setBaseStyle("noBorderCell");
    
 jsonTree.setShowAllRecords(true);
 jsonTree.setDataSource(xjsonDS);


 button.addClickHandler(new com.smartgwt.client.widgets.form.fields.events.ClickHandler() {
	public void onClick(
com.smartgwt.client.widgets.form.fields.events.ClickEvent event) {

	jsonTree.fetchData(form.getValuesAsCriteria());
			
		}
    });

[smartgwt.dev]

Please pick up the latest build. This has been fixed in SVN.