the system was working, stopped working with the latest version 3.1.1

Example is work extjs 3.1.0:

Code:
Ext.Ajax.request({
    url      : 'page.php'
    ,method  : 'POST'
    ,scope   : this
    ,success : function(response) {                        
        var responseObject = Ext.decode(response.responseText);

        if(!(Ext.isObject(responseObject))) {
            //object OK
        }

        if(responseObject.success === true) {
            //return true
        }
    
    ...
Example does not work extjs 3.1.1:

Code:
 Ext.Ajax.request({
    url      : 'page.php'
    ,method  : 'POST'
    ,scope   : this
    ,success : function(response) {                        
        var responseObject = Ext.decode(response.responseText);

        if(!(Ext.isObject(responseObject))) {
            //not object
        }

        if(responseObject.success === true) {
            //return false
        }
    
    ...