I use 4 different milonic .js menu scripts on my site (I know, overkill, but still) and some load before others. the problem is that if you move your mouse over one to bring up the sub menus before the others load, then the other menus load COMPLETELY wrong. usually the sub menus from the menu you have moused over show up instead of one of the other menus.
To see this you can visit http://www.guildsofganareth.com/update/test/ , the top menus load first, try it

hope this helps and my explanation isnt too confusing.
This happens on both rc_2 and rc_3, I dont know about earlier