dns trouble -- hostnames not resolving for everyone

I recently opened another ticket and was advised to simply add A records for ns1.nxnet.us and ns2.nxnet.us to my nxnet.us domain but it has been over 48 hours and I haven't seen any results.

Here is my setup-->

I have Virtualmin Pro on a server @ 74.55.117.83-84 using .83 as the shared IP and .84 as the ns1.nxnet.us IP.

I also have Virtualmin GPL on a server @ 74.55.117.85 that is acting as a cluster DNS slave.

I have set up ns1.nxnet.us and ns2.nxnet.us at namecheap and they seem to be working for me (domains are being referred to my server's authority and it seems to be working)... but some of the domains (not all?) appear down for some people.

Who's fault is this?

Can you take a look at my configuration and help me out?

I am willing to grant Joe/Jamie access to have a look.... cause I'm just stumped!

Status: 
Closed (fixed)