I have setup WP multi user as a sub-domain config on mysite.com using the 'activae muti-site plugin). I established a wildcard domain (A record) so anything.mysite.com does work/register and returns a 'Default web page' from my host which also notes 'If you feel you have reached this page in error, please contact the web site owner:'like it hasn't been fully configured yet.
I create a new sub-site in my WP-MU configured as (eg) blog.mysite.com
Go to this new domain/sub-site and it still returns the 'default' page, never actually going to the new site.
I have tried many parked/addon domain registrations for it, the wildcard (as noted above) and also variations of the Domain Mapping plugin just to be sure.
In all cases the root site (mysite.com) continues to run, and also another independant sub-site domain at myname.mysite.com is working correctly too, but not any sub-domain (whatever.mysite.com) never seems to become activated or correctly dns/wp/account mapped.
Any help would be great.