New blog created by user not built

I just did a fresh install of WP 3.1.2 and followed the instructions to activate multisite. (Copied the .htaccess content, etc.)

I chose subdomain and my server's support team added wildcard DNS for my domain.

As the admin, I created a new user. (The intention was to create a default theme for use when users create a blog, using the "default theme" plugin.)

I then added a site for this user. No errors reported during this quick process.

I go to view the dashboard of this new blog, yet I receive a 404 error.

What am I missing?