One </div> too much

Taking a look now, thanks.

I'm not sure I agree. At first it looks like </div></div> is one-too-many, but I believe what's going on is that I started another div before the menu link_title field -- that's how I add that grey box in to surround the "original" menu item form (with the "Add new menu link" button tucked in at the bottom).

Of course, that whole grey box thing is pretty inelegant, and probably should go, but my initial concern is to just make everything as stable as possible, and then get feedback from people about what the best approach is for this form. (My initial motivation was to preserve the original form for people who only care about one link, and then provide the "multiple" editor below it.)

That being said, are you sure you're not using the modified version uploaded in the other support thread? That one does not have the grey box, but still has the two end-divs, so that one appears to need the patch.