Disabled Items Combo Box

We needed a ComboBox that could disable items in the drop down list.  I could not find one out there so I created one.  I started out by using the List created by Alex Harui here:

http://blogs.adobe.com/aharui/2007/06/disabling_list_selection.html

This wasn't a straight forward task since ComboBox destroys it's dropDown list and doesn't give you a hook or way to add functionality to it.  If you know a better way please comment.  I override methods where the dropdown is newly created.  At that point I set the disabledFunction to the dropDown list.  

Here is an example App:

Disabled Items Combo Box Example

You can get to the source code by right clicking on the example app and choosing View Source.