I have a fresh new install of WP 3.05.
I foll wed the instructions to get MultiSite up and running.
Odd thing happens when i got to create a new site... Nothing!
I don't get any errors, yet there is not site created at the subdomain.
The sub domain just points to the plesk server page as is there was not site created.
see for your self.
Main site: http://www.power-seller.net
I thought it might have been some thing to do with my host and plesk But then i remembered that i already have one site running using multisite. although that install was done under 3.04