I just tried to implement on my localhost (Mac OS X - Leopard - using MAMP). I put stuff here: Home > Sites > Website Name
No matter what I did, I could not get the home page to serve from the cache. I never encountered your weird URLs.
But I did get it working on sub pages. I did have to replace "**sitedir** in the DEV section of the htaccess, it wouldn't work without (even if I had rewritebase specified).
Just to make sure, I confirmed that on my live/hosted site, the home page is indeed being served from the cache.
Not sure what else to tell you to try except put it up on a hosted site and see if it works for you there.