I'm trying to implement an advanced example of jquery.ui.autocomplete widget with categories ( http://jqueryui.com/autocomplete/#categories ). My code basically looks just like in this example's source code but for some reason, when i'll type something in input field, autosuggest don't work and i'm getting this error in object inspector javascript console:

Object #<Object> has no method '_renderItemData' 

Have you any idea what am i possibily doing wrong? The basic example works fine on my website. Thanks in advance.