I'm not 100% sure if this is a WordPress bug or a WooCommerce bug, but I've noticed when I try to assign a category to a product that most of the sub-categories get all mushed together whereas others are listed under their parents so it's easy to tell which go where. This is really frustrating because I have a lot of sub-categories that have the exact same names with different parent categories.
See examples here:
1. My product categories: http://i47.tinypic.com/mcgor5.jpg
2. How they show up when assigning in Edit Product: http://i49.tinypic.com/jucuv6.jpg
Any help would be greatly appreciated, thanks!