Binabik: No, you don't have to, Firefox does this all on itself. And perhaps I didn't express myself clear enough: For both Firefox versions 1.5 and 2.0 there is an update available which should fix your problem. For Firefox 2.0 it's 2.0.0.2. So check your version number ("Help"->"about Firefox"). If it starts with 2.0 but is not 2.0.0.2, an update might solve the disappearing bookmarks. Something caused that in particular situations the profiles were created with a write protection, so that firefox couldn't store the bookmarks permanently. This should be gone with 2.0.0.2/1.5.0.10. If it still doesn't store them, you could manually check if the profile folder is write protected..