Hi folks! we're refactoring an application that uses these paths in order to use Ext, don't know the exactly version but it seems to be a beta or RC version.
Code:
    
     <script type="text/javascript" src="/app_name/js/ext-4.1-pr1/ext.js"></script>
    <script type="text/javascript" src="/app_name/js/ext-4.1-pr1/ext-all.js"></script>
The problem is when using TreePanel expandAll method and selecting a node using getSelectionModel().select(node).

Sometimes it works great and some others it crashes when using IE9, not happening the same in IE8 or IE7.

It's throwing the next error message in IE9:
<< Unable to get value of the property 'viewIndex': object is null or undefined >>
and it's in ext-all.js.

These is the callstack that IE9 shows:
> indexOf
onExpand
fire
continueFireEvent
fireEvent
onNodeExpand
fire
continueFireEvent
fireEvent
Anonymous Function
callback
onBeforeNodeExpand
fire
continueFireEvent
fireEvent
Anonymous Function
fire
continueFireEvent
fireEvent
expand
expandChildren
expand
expandAll

Thanks in advance.