"Domain mapping" plugin (latest version) doesn't work at all

When I try to map one site to its domain name, I always have this error :
"Domain name is unavailable to access."
"We can't access the new domain. If you've just purchased it, please, wait while it will be propagated. If it is already propagated, please, check your DNS records to be sure that the domain is configured correctly."

But my domain is properly configured :
- A record pointing to my dedicated server
- wildcard CNAME pointing to the network's domain name

Everything worked fine with the last version...
WPMUDEV Y U DO DIS ?