Domain Mapping - unavailable to access

That's the toughest part so far. Having problems with domain mapping. I did everything as described on that page:
https://premium.wpmudev.org/project/domain-mapping/#usage

I come exactly to that part: Domain name verification alert.
For the domain I want to map I see a default page already, but not the subfolder. My wpmu installation is on /subfolder.

As user I can access the the domain mapping, I see the IP and can enter my domain and than I get the verification error. Before I created an A record pointing to the IP of my server. (still not sure if I did it right)
Hostename * record type A and IP and
mydomain.org record type A and IP

I am pretty confused now, just thinking a user can't do more than that.. I guess there is anything I did wrong. help..