Domain Mapping: A Record not taking effect

We're trying to get domain mapping working for our first client needing a preexisting domain to be mapped to the site we're building for them. Problem is, I can't even get the A Name record I added via the domain registrar (eNom) to take effect. I added the record several days ago (well over 48 hours, so it's not a propagation issue, I think).

Here's the record I added:
-- host name: / address:; Record Type: A (Address)

There is just one other preexisting record in the listing of Host Records (of type TXT), but this should have no bearing on the domain mapping, right?

I'm sure the domain isn't resolving correctly since pulling it up returns nothing ("Error code: DNS_PROBE_FINISHED_NXDOMAIN" from the browser) and it's obviously not finding my WordPress install.

Thanks for any advice!