So, just to confirm:
I should be logged out of the site admin to start.
Copy the 5 admin files (well 4 for me as there is no Spanish on mine - Russian instead!)
Login to admin which should create the database entry
Add 2 store-side files

I'm pretty sure that's exactly what I did but I'll give it another go.

Using ZC 1.5.4 with the M-o-z-e-n theme (not sure if that makes any difference). I noticed from an earlier post that someone was having problems with SEO urls. I have Ceon Uri-mapping running if that's likel;y to affect anything.