So what about when I run a DNS Report on this customer and get the following:
NS records at parent servers Your NS records at the parent servers are:
ns4.xxx. [204.10.xxx.xxx (NO GLUE)] [US]
ns3.xxx. [204.14.xxx.xxx (NO GLUE)] [US]
ns.xxx. [204.14.xxx.xxx (NO GLUE)] [US]
[These were obtained from tld4.xxx.org]
WARNING. The parent servers (I checked with tld4.xxx.org.) are not providing glue for all your nameservers. This means that they are supplying the NS records (host.example.com), but not supplying the A records (192.0.2.53), which can cause slightly slower connections, and may cause incompatibilities with some non-RFC-compliant programs. This is perfectly acceptable behavior per the RFCs. This will usually occur if your DNS servers are not in the same TLD as your domain (for example, a DNS server of "ns1.example.org" for the domain "example.com"). In this case, you can speed up the connections slightly by having NS records that are in the same TLD as your domain.
I do not see how Bell South has anything to do with this...