DNS issues with Heroku + FreeDNS.afraid.org

Question

Trying to use these two in conjunction. Pointed domain to ns1 through ns4.afraid.org, have the following setup

cardbox.io (G)  A 75.101.145.87
cardbox.io (G)  A 75.101.163.44
cardbox.io (G)  MX 5:alt1.aspmx.l.google.com
cardbox.io (G)  MX 5:alt2.aspmx.l.google.com
cardbox.io (G)  MX 1:aspmx.l.google.com
cardbox.io (G)  MX 10:aspmx2.googlemail.com
cardbox.io (G)  MX 10:aspmx3.googlemail.com

, but Heroku complains...

cardbox.io has no records pointing to Heroku's servers. Please add either a CNAME to proxy.heroku.com or A records to 75.101.163.44, 75.101.145.87. Please check that you've configured this domain name with your DNS provider.

Anything I'm doing wrong?