Alpha 4 is available. For some reason the update script likes to use a cached copy of the html update page, meaning that it won't actually notice when it's time to upgrade. I've changed the update page to a .php page and in my limited testing here at the house it appears to be working better.
So, go on over to
http://userscripts.org/scripts/source/12975.user.js and upgrade.
I finished pulling most of the nasty hacks out and the script now runs 10x faster on average than Alpha3, it's about 25x faster than the first version and has a lot more functionality.
I've also added the ability to turn the Show/Hide links on or off.