Hi all. I have some problems with loading data into JsonStore:

Code:
var korisnikStore = new Ext.data.JsonStore({
        url : 'korisnik.json',
        baseParams : {
            korisnikId : 1
        },
        fields : ['KORISNIK_ID'],
        autoLoad : true,
        listeners : {
            load : { 
                fn: function(e) {
                    console.log(e);
                }
            }    
        }
    });
Json response:
Code:
{"3":0,"2":1,"1":1,"KORISNIK_ID":1}
But korisnikStore.data.items.length is 0, and there are no data in it. I also tried with type: 'float', but nothing changes.

I see request/response in firebug and it is ok, but store doesn't get populated with anything. What could be wrong?