I'm also having huge difficulty with domain mapping. The process seems simple enough on the wordpress side, my difficult lies with my current provider.
I have a domain registered. I've asked the provider to update the nameserver listing to the wordpress servers, what i get from them is this reply:
I have chatted to our DNS department, and unfortunately, we are unable to use one of the IP addresses mentioned below, as they are IP addresses for Name Servers. We cannot change the Name Server details on your domain. If your new ISP is unable to give a single IP address for www records to be pointed to, the only alternative is to transfer the domain over to them.
Please confirm with them if they do host domains and then we can start the domain transfer process. Please let me know as soon as you have had confirmation from them.
Can anyone please give me a solution. Will it be easier to transfer my domain, if so who should i have it transfered to? Note that i currently have my mx record manged by google apps - for email.