Just installed a brand new copy of WordPress to enable multisite. I've been using WordPress since like 2005 for my own website. So I'm not exactly a novice, though there is a fair amount I simply haven't needed...
Anyway, it's installed in the docroot (index.php resides in /home/siteuser/public_html) and I enabled wildcard subdomains.
The main site: scriptersblogs.com
I created a test site at adamh.scriptersblogs.com and it almost works. If I switch over to the user's dashboard (adamh.scriptersblogs.com/wp-admin) it works perfectly. But try to go to just adamh.scriptersblogs.com (ie click "Visit Site" from within the dashboard) I get the cPanel Default Web Site Page.