I have followed your instructions (installed the plugin, placed php call on the archive page, uploaded scripts and linked them in my header). The archive list shows up but without the accordian effect. All I know is that there are a couple of undefined classes: moo.fx.js line 57 moo.fx.pack.js line 10 .. though I doubt that that actually makes any difference.
I had been using Hicksdesign style archives but was fed up with the scrolling too. Any ideas? Known bugs?