Can't Save Submenu

Hi there!

I’m having a problem with my menu that just started today. I’m trying to create a “categories” tab in my menu that, when you hover, displays a list of my categories. I was able to do this yesterday, but today when I drag, say, “uncategorized” under the “categories’ tab and save it, it doesn’t save. I instead have my “uncategorized” beside “categories” in my menu instead of under it. The blog I’m having trouble with is Passamaquoddy Liberation.

Any help would be greatly appreciated!