dig failed the usability test! - adding A record for nameserver

I'm setting up a new server (VPS) on CentOS 5 with WHM 11, latest RELEASE version. When trying to add an A record for my nameservers in "Main >> Server Configuration >> Basic cPanel/WHM Setup" I get the following error:

Code:

dig failed the usability test!
	Cpanel::DnsRoots::getdigutil() called at /usr/local/cpanel/Cpanel/DnsRoots.pm line 287
	Cpanel::DnsRoots::dig(undef, 'com', 'NS', 86400) called at /usr/local/cpanel/Cpanel/DnsRoots.pm line 117
	Cpanel::DnsRoots::fetchnameservers('ns1.maindomain.com', 1) called at /usr/local/cpanel/Cpanel/DnsRoots.pm line 61
	Cpanel::DnsRoots::resolvenameserver('ns1.maindomain.com') called at whostmgr/bin/whostmgr2.pl line 2943

I've had little to no luck finding references to this and no answers. The error does not come up on a similarly configured VPS using FC 2 (same WHM version). Any ideas?