Category becomes invisible when adding a subcategory with the same name as parent category

Steps to reproduce:

• login
• go to Blog Space
• on the Blog Categories Panel from left, click "Edit Categories"
• add a subcategory to News called News. Basically a category with the same name as its parent name

You will see that News category (parent) will disappear along with its subcategory.

This happens on Chrome 16 and Firefox 9.0.1. Does not happen on IE8 and IE9

We should have a Selenium 2 test for this after it is fixed