I am wondering why I am reading error messages stating my wikis don't exist.

I followed instructions installing the wiki plugin into my website, and activated it (I have WPMU plugin). I keep receiving messages that my pages are not found:

http://amiscellany.info/musicwiki/wiki/2-by-bukowski/

Is there a theme that I’m missing? I am a bit lost, as this is my first purchased plug, and it’s not quite working as advertised.