I also observe the same behaviour as described above. Always affects the Bookmarks menu when opening Firefox 3.0, but I have also observed the same problem with the File menu (opens "New window" instead of expanding the File menu).
I also observe the same behaviour as described above. Always affects the Bookmarks menu when opening Firefox 3.0, but I have also observed the same problem with the File menu (opens "New window" instead of expanding the File menu).