With Public Beta 5, all of a sudden my Safari extensions (almost all of them) disappeared. The physical files are still located in the ~/Library/Safari/Extensions folder as they always have been, but they don't show up in Safari's preferences, or in the toolbar. In fact, where the icons used to live in the toolbar has been replaced with spacers. Now I say almost all of them, because several remain—seemingly random ones (some old, some new). Anyone have any insight?