I mainly use FF2 and IE6 / 7, and even though the Dropdown Links don't work properly in IE6, the Page Addresses still do. So I've tested it with all three, pre-release, and they all worked from what I could tell. However, the Release that we Launched is a little different from the Version we all tested internally. So it must've been part of the coding that was removed for release.
I cannot say for sure, but that's the scenerio I'm coming up with.