Saft does it pretty well, works after 10.4.5 (and is generally updated within a day or two after any Safari update), and is a Universal Binary. It has a bajillion other features as well, like ad-blocking, full-screen mode, draggable tabs, search keywords in the address box and multiple search engines in the search box, and probably more..
It's $12, which might seem kind of annoying after you've paid for Safari Extender. But you may as well try it, eh? I'm not sure what the limitations on the demo are, but you can get it from
this page.
Good luck.